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What are the atoms in water molecules?
Hydrogen & Oxygen
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Are the atoms in water molecules charged and why? If so what are the charges for each atom?
Hydrogen - delta positive and Oxygen - delta negative because Oxygen is pulling the electrons slightly more.
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What is the type of bond in water molecules? How do we know?
Hydrogen bonds - these bonds are covalent. They share electrons.
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What type of attraction is there between the atoms? What is this called?
There’s a WEAK ELECTRICAL ATTRACTION between a HYDROGEN in ONE molecule and the OXYGEN in ANOTHER molecule. This is a HYDROGEN BOND.
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In what state does hydrogen bonding occur in water molecules?
In a LIQUID STATE, water molecules undergo hydrogen bonding with surrounding molecules. The bonds break and reform as the molecules move around.
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What properties do water molecules have? (5 properties, some may have more than one as one point)
Cohesion & Surface Tension 2. Heat & temperature 3. Polar Nature/Solvent Properties 4. Density & Viscosity 5. Reactivity
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Cohesion & Surface Tension: What does it mean? How does water behave?
A drop of water DOESN’T spread out but is instead looks SPHERICAL. Molecules at the SURFACE of the water are HYDROGEN BONDED to the molecules BENEATH them – they are therefore MORE ATTRACTED to the water molecules BENEATH than in the AIR.
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Cohesion & Surface Tension: Which property does it explain?
Why the SURFACE of water has the ability to resist force applied to it, leading to surface tension
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Heat/Temperature : What does it mean in terms of structure? What does it measure?
1. As water molecules are heled together QUITE TIGHTLY by HYDROGENN BONDS you have to use A LOT of HEAT ENERGY to BREAK THEM. 2. Water temperature is a MEASURE OF THE KINETIC ENERGY OF THE WATER MOLECULES.
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Heat/Temperature : How does water behave when heated?
When water EVAPORATES heat energy (AKA LATENT HEAT OF VAPORISATION) helps the molecules to BREAK AWAY from EACH OTHER and become a GAS.
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Heat/Temperature : What is specific heat capacity? How does this effect water?How much energy is needed to heat up 1kg of water by 1 degree (include unit of measurement)?
In terms of SPECIFIC HEAT CAPACITY, a relatively LARGE amount of HEAT ENERGY is needed for water molecules to start evaporating as HYDROGEN BONDS are STRONG, COVALENT bonds. 4.2 kJ are needed.
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Solvent Properties : What does it mean when it's said that water has solvent properties? (Include 2 examples)
Solutes can dissolve inside water e.g. sodium chloride in water (ionic solute) and glucose (covalent solute)
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Solvent Properties: What is the property and why is it important?
Water’s usefulness as a solvent – molecules and ions can move around and react with water
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Solvent Properties: How does water behave and why?
Water’s POLAR NATURE means that both CHARGED parts of water molecules are ATTRACTED to the CHARGED parts of the SOLUTE. The ATTRACTION helps keep the CHARGED parts of the SOLUTE separate because the MOLECULES CLUSTER around these parts in the solute.
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Density and Viscosity : What does this mean in reference to water's structure?
Water is VERY DENSE – which means structurally the HYDROGEN MOLECULES are CLOSE TOGETHER.
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Density and Viscosity : How do most liquids behave and how does water differ?
MOST LIQUIDS get DENSER as it gets COLDER. This isn’t ENTIRELY the case with water. Water gets DENSER until it hits 4 degrees (to freezing point).
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Density and Viscosity : Why does water behave differently to most liquids? (link to structure and another property)
Because of water’s POLAR NATURE which causes them to align themselves in a STRUCTURE which is LESS DENSE than liquid water (ICE is LESS DENSE than water)
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Which is LESS dense - Water (as a liquid) or ice?
Ice
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*I'll fill in the gaps
Question is: What is the role of water in a living orgamism
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New topic: Flip to reveal
CARBOHYDRATES!!
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What atoms make up carbohydrates?
Carbon, Hydrogen and Oxygen (CHO)
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Carbohydrates are 'hydrated carbon' - what does this mean?
For every carbon atom, there are TWO hydrogen atoms and one oxygen atom.
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The functions of carbohydrates are 'three-fold', this means they have three functions, what are they? Give examples of specific carbohydrates for each function.
1. Energy source (glucose) 2. Energy store (starch and glycogen) 3. Structural units (cellulose in plants and chitin in insects)
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Some carbohydrates are part of OTHER MOLECULES. Name two.
Nucleic acids & glycolipids
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What are the three main carbohydrate groups?
Monosaccharides, Disaccharides and Polysaccharides
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What do the COMMON monosaccharides and disaccharides names end in (suffix)?
-ose
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Which is the simplest type of carbohydrate?
Monosaccharides
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What is the role of monosaccharides in living organisms particularly and what makes them well suited to this role?
Source of energy. Their large number of carbon-hydrogen bonds make them suited to this role.
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What type of carbohydrates are monosaccharides and what do they taste like?
Sugars and they taste sweet.
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Are monosaccharides soluble? If yes, are there any exceptions for what they are/aren't soluble in?
They are soluble in water but insoluble in non-polar solvents.
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What structure do monosaccharides have? What is the chain like - straight or coiled, are they cyclic etc?
Straight chains and ring/cyclic forms.
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In the backbone of a monosaccharide are the carbon atoms single or doubled bonded? (There is one exception to this answer - what is that carbon atom bonded to and what group does it form?)
Single bonded carbon atoms. There is one double bonded carbon atom that is bonded to an oxygen atom to form a carbonyl group.
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How many CARBON atoms does a) hexose b) pentose c) tetrose d) triose sugars have?
a) hexose - six b) pentose - five c) tetrose - four d) triose - three
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Glucose is a type of which sugar - Hexose, pentose or triose?
Hexose.
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In solution, what do pentoses, hexoses, triose and tetrose exist as (in terms of chains (most likely)- coiled, spiralled or straight)
Triose and Tetrose in straight chains. While, Pentoses and Hexoses are MORE LIKELY to be found in a ring or cyclic form.
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What are isomers?
Molecules with the same formula., but whose atoms are arranged differently in space.
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Can isomers only exist in ring/cyclic forms, straight chain form or both?
Both
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In the straight chain form how can the arrangement being changed (isomers - what atoms or groups can be changed?
-H and -OH can be reversed
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In a ring shape form how can the arrangement being changed (isomers - what atoms or groups can be changed? (Make reference to how the ring is formed and how isomers effect things)
The ring is formed when the oxygen attached to carbon 1 bonds to carbon 1. Because the -OH and -H on carbon 1 can be above or below the plane of the ring when the ring forms, there are two isomers a- and b- glucose..
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How does the isomers in ring form effect polymerisation (refer to a-glucose and b-glucose and the arrangement)
It effects how glucose molecules polymerise into starch or cellulose. The carbon 1 bonds to the -OH on the bottom in a-glucose and the -OH on top in the b-glucose.
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How are disaccharides made?
They are made when two monosaccharides join together.
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What reaction bonds monosaccharides together to create disaccharides?
Condensation reaction.
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What bond is formed after a condensation reaction between two monosaccharides?
A glycosidic bond
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What happens during a condensation reaction between two monosaccharides?
Two HYDROXYL groups line up next to each other, from who
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How do disaccharides taste and are they soluble?
Like monosaccharides, they taste sweet and are soluble.
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Name three of the most common disaccharides - which are reducing and which are non reducing?
Maltose (malt sugar) and Lactose (milk sugar) are reducing. Sucrose is non-reducing.
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There are lots of different combinations which determine the disaccharide made. How are maltose, cellobiose, lactose and sucrose made (with reference to alpha and beta glucose, beta galactose and fructose)
Maltose = a-glucose + a-glucose. Cellobiose = b-glucose + b-glucose Lactose = b- galactose and a - glucose Sucrose = a-glucose + fructose
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What reaction bonds monosaccharides together to create disaccharides?
Condensation reaction.
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What bond is formed after a condensation reaction between two monosaccharides?
A glycosidic bond
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What happens during a condensation reaction between two monosaccharides?
Two HYDROXYL groups line up next to each other, from which a water molecule is removed. This leaves an OXYGEN atom acting as a link between the two monosaccharide units.
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How do disaccharides taste and are they soluble?
Like monosaccharides, they taste sweet and are soluble.
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Name three of the most common disaccharides - which are reducing and which are non reducing?
Maltose (malt sugar) and Lactose (milk sugar) are reducing. Sucrose is non-reducing.
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There are lots of different combinations which determine the disaccharide made. How are maltose, cellobiose, lactose and sucrose made (with reference to alpha and beta glucose, beta galactose and fructose)
Maltose = a-glucose + a-glucose. Cellobiose = b-glucose + b-glucose Lactose = b- galactose and a - glucose Sucrose = a-glucose + fructose
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How are the bonds in disaccharides broken (how is the reaction reversed)?
By a hydrolysis reaction.
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What is required in a hydrolysis reaction between two monosaccharides and what happens? What is obtained by the hydrolysis of cellulose?
Water is required. The water provides a hydroxyl group (-OH) and a hydrogen (-H), which help the glycosidic bond to break (dissolve). Cellubiose
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What is also present during condensation reactions and hydrolysis?
A catalyst - enzymes.
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What are polysaccharides?
Polymers of monosaccharides
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What are polysaccharides that are made solely of ONE kind of monosaccharide? Give an example
Homopolysaccharides. An example is starch
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What are polysaccharides that are made of MORE THAN ONE monomer called? Give an example
Hetereopolysaccharides. An example is hyaluronic acid (in connective tissue).
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Glucose is a source of energy as it is a reactant in respiration. What is the energy that is released used to make?
ATP - the energy currency of the cell
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How do living organisms create energy stores (generally)?
They join lots of glucose monosaccharides together into polysaccharides.
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What do plants store energy as and where?
Plants store energy as starch in chloroplasts and in membrane bound starch grains.
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What do humans store energy as and where?
Humans store energy as glycogen in cells of the muscles and liver.
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The structure of some polysaccharides lends itself to energy storage (refer to glycogen and starch)
Glycogen in animals and starch in plants (comprising amylose and amylopectin) occur within the cells in the form of granules.
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Glycogen and starch are compact and both occur in dense granules within the cell. What does this structural benefit mean?
It means they do not occupy a large amount of space.
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Polysaccharides hold glucose molecules in chains. What does this structural benefit mean?
It means that they can easily be 'snipped off' from the end of the chain by hydrolysis when required for respiration.
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Hydrolysis reactions are always catalysed by what?
Enzymes
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In Glycogen some chains are branched and some are unbranched. Which is which? (There are 3 things to sort : amylopectin, amylose, glycogen)
Amylopectin is unbranched. Amylose and glycogen are branched.
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What are the structural benefits of amylose and glycogen having branches? (2 points to make)
Branched chains tend to be more compact, but also offer the chance for lots of glucose molecules to be snipped off by hydrolysis at the same time, when lots of energy is required.
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Which enzyme is responsible of hydrolysing 1-4 glycosidic linkages?
Amylase
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Which enzyme is responsible of hydrolysing 1-6 glycosidic linkages?
Glucosidase
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What is a 1-4 glycosidic linkage?
A linkage between carbon 1 of one glucose and carbon 4 of another.
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What is a 1-6 glycosidic linkage?
A linkage between carbon 1 of one glucose and carbon 6 of another.
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Which is LESS soluble : Polysaccharides or monosaccharides?
Polysaccharides are LESS soluble than monosaccharides.
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Why are polysaccharides less soluble than monosaccharides? (2 points - refer to the fact that they are granules in your second point)
Polysaccharides are less soluble than monosaccharides because of their size and the fact that they are in granules mean regions which could hydrogen-bond with water are hidden away inside the molecule.
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Why is it good that polysaccharides are less soluble than monosaccharides?
If they were more soluble, many glucose molecules would dissolve in the cytoplasm which would reduce water potential, and excess water would diffuse in, disrupting the normal workings of the cell.
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What is water potential?
Water potential is a measure of the potential energy in water as well as the difference between the potential in a given water sample and pure water.
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Sometimes the amylose molecule may form a double helix. What does this mean?
This presents a hydrophobic external surface in contact with the surrounding solution.
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Click to reveal Carbohydrates Subtitle!
Types of polysaccharide!! (Go to my resources for a table that explains their structure in terms of spirals, bonds and arrangement)
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Types of polysaccharide: Amylose (part one) Is it found in humans or plants, what is the length of the chain, what is the polymer of monosaccharides that make it up, how is it similar to maltose in terms of it's glycosidic bonds?
Amylose is found in plants. Long chain made up of of a-glucose. Like maltose, it has glycosidic 1-4 linkages
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Fun Question: The core of a glycogen or amylopectin molecule is resistant to hydrolysis by enzymes. What is such a unit called and what is it one of the major component of?
Such a unit is called a 'limit dextrin' and it's one of the major components of mucus.
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Fun Question: Glycogen is stored in what two places, the liver and what? It may form up to what % of the mass of the liver?
Muscles. It may form up to 7% of the liver.
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Where is cellulose found?
In plants in the cell wall
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Is cellulose soluble? is it tough and fibrous or globular?
It's insoluble. It's tough and fibrous.
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Is Cellulose a homopolysaccharaide or heteropolysaccharide? What's it made up of and how much of it? What bonded it together? What bonds are there?
Homopolysaccharide. 15,000 b-glucose molecules. Bonded by condensation reaction w/glycosidic bonds
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Describe what would happen on a diagram once the condensation reaction takes place between two b-glucoses (cellulose) - (hint: rotation)
The second b-glucose molecule is rooted forwards by 180 degrees compared to the first - as if it's doing a handstand
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Are cellulose chains spiralling or straight? How do they lay in arrangement? What is the direct difference in structure a result of?
Straight and they lay side by side. This is a direct result of bonding.
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What does hydrogen bonding between the rotated b-glucose molecules in each chain do? How?
It gives the chain additional strength, and stops it spiralling. The hydroxyl group on carbon 2 sticks out. enabling hydrogen bonds to be formed between chains.
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Hydrogen and Hydroxyl groups on carbon 1 are reversed in a-glucose, how does this DIFFER in b-glucose? What does this mean?
In b-glucose, hydrogen and hydroxyl groups on carbon 1 are inverted. This means that every other b-glucose molecule in the chain is rotated by 180 degrees. Stops it from spiralling
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What three things stop cellulose from spiralling? (Really two things in effect)
Hydrogen bonds. The fact that the hydrogen and hydroxyl groups are inverted and the fact that the b-glucose 1-4 glycosidic bond help.
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When 60 to 70 cellulose chains are bound together by hydrogen bonding between b-gluclose molecules what do they form? How big are these formations?
Microfibrils, which are 10-30nm in diameter.
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Microfibrils in cellulose often bundle together into macrofibirils containing up to 400 microfibrils. What do these 'bundles' do? (hint: think cell walls)
They are embedded in pectins (like glue!) to form plant cell walls.
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How do macrofibrils provide extra strength to the cell wall?
They run in all directions criss-crossing the wall for extra strength.
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For what two reasons of microfibrils and macrofibrils have very high tensile strength?
Both because of the strength of the glycosidic bonds and because of the hydrogen bonds between chains.
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Fun fact: Flip to reveal fun fact about MACROfibrils
Microfibrils are stronger than a steel of wire of the same diameter.
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Why is it difficult to digest cellulose? (Fun fact: most animals do not even have an enzyme to catalyse the reaction)
Because the glycosidic bonds between the glucose molecules are less easy to break. Indeed, most animals do not even have an enzyme to catalyse the reaction.
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Why are the key features such as micro/macrofibrils and cellulose indigestible ability help the cell wall do its job?
Plants do not have a rigid skeleton, each cell needs to have strength to support the whole plant. There is space between macrofibrils for water and mineral ions to pass on their war into and out of the cell. This makes the cell wall fully permeable.
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The cell wall has high tensile strength. Why is this important and how?
It prevents cells from bursting when they are turgid, again helping to support the whole plant. Turgid cells press against each other, supporting the structure of the plant as a whole. The wall also protects the delicate cell membrane.
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The macrofibrils can be reinforced with other substances for extra support or to make the walls waterproof. Give examples
Will do later. Use p. 60 in the textbook
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Other structural polysaccharides: Bacterial Cell Walls
p. 60
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Other structural polysaccharides: Exoskeletons
p. 60
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New topic. Click to reveal
Lipids 1: Triglycerides
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What are lipids? Give 4 examples of molecular structures they include.
Lipids are a group of substances that are soluble in ALCOHOL rather than water. They include triglycerides, phospholipids, glycolipids and cholesterol.
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What is a macromolecule?
A very LARGE, organic molecule
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What is a phospholipid?
A molecule consisting of glycerol, two fatty acids and one phosphate group.
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What atoms make up lipids (make reference to amount)
CHO - Large amounts of carbon and hydrogen and smaller amounts of oxygen.
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Are lipids soluble in water? Why?
Lipids are insoluble in water because they are not polar, and so do not attract water molecules.
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Are lipids soluble in alcohol?
Yes, Lipids are soluble in alcohol
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What are the THREE most important lipids in living things? These AREN'T polymers but what do they have that are similar to polymers. What are these examples of?
Triglycerides, phospholipids and steroids. They are similar because they have different components bonded together.They are examples of macro-molecules.
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What are triglycerides made up of?
One glycerol and three fatty acids.
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There are many different types of fatty acid. We can make many of them in our bodies, but some must be ingested 'complete'. What are these fatty acids called?
Essential fatty acids.
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What is glycerol a type of and what does this mean it has and what is that important? How many carbon atoms does it have?
Glycerol is a type of alcohol which means it has free-OH groups (three to be exact) which are important to it's structure
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What is a fatty acid? What is it made of/structure? How long is it?
A fatty acid is carboxyl. It has a carboxyl group (-COOH) on one end attached to a hydrocarbon tail, made of only carbon and hydrogen atoms. It may be anything from 2 to 20 carbons long.
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What does the carboxyl group in fatty acids do? What structure does this create and how do we know this?
The carboxyl group ionises into H+ and a -COO- group. This structure is therefore an acid because it can produce free H+ ions.
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How do we know if a fatty acid is saturated?
This means that there are no C=C (double bonds between carbons) in the molecule.
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How do we know if a fatty acid is unsaturated? What are the effects?
This means that there is no double bond between two of the carbon atoms instead, which means that fewer hydrogen atoms can be bonded to the molecule.
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What does one C=C bond do to a fatty acid? Give examples.
It makes it monounsaturated e.g. oleic acid.
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What does MORE than one C=C bond do to a fatty acid? Give examples.
It makes it polyunsaturated e.g. linoleic acid.
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How does having one OR more double carbon bond / C=C bonds do to the shape of the hydrocarbon? What effect does this have?
It changes the shape by giving it a 'kink' where the double bond is. The effect of these kinks push the molecules apart slightly, it makes them more fluid.
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Animal lipids contain lots of SATURATED fatty acids. What state are these fatty acids often in at 20 degrees.
Solid.
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What is the effect on melting point when there are MORE unsaturated fatty acids.
The melting point is lower.
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What does a triglyceride consist of?
ONE glycerol molecule bonded to THREE fatty acids.
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Explain the synthesis of a triglyceride (refer to the type of reaction and the groups it happens between)
A condensation reaction between the -COOH group of the fatty acid and the -OH group of the glycerol.
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What is it about triglycerides that give it the name of TRIglycerides?
As there are THREE -OH groups, THREE fatty acids will bond, hence the name triglyceride.
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What is produced during the condensation reaction?
Water / A Water molecule
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What type of bond is formed within triglycerides, What is the SPECIFIC name of the bond?
A covalent bond called an 'ester' bond.
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Extra information about fatty acids that you kind of need to know! :)
In some cases the same TYPE of fatty acid may bond to each -OH group, or the fatty acids may be different
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Other cards in this set

Card 2

Front

Are the atoms in water molecules charged and why? If so what are the charges for each atom?

Back

Hydrogen - delta positive and Oxygen - delta negative because Oxygen is pulling the electrons slightly more.

Card 3

Front

What is the type of bond in water molecules? How do we know?

Back

Preview of the front of card 3

Card 4

Front

What type of attraction is there between the atoms? What is this called?

Back

Preview of the front of card 4

Card 5

Front

In what state does hydrogen bonding occur in water molecules?

Back

Preview of the front of card 5
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