Lipids - Triglycerides

?
  • Created by: shyde7
  • Created on: 28-03-16 11:19
Lipds contain larger amounts of which elements?
Carbon and Hydrogen
1 of 36
Lipds contain smaller amounts of which element?
Oxygen
2 of 36
Why are lipids insoluble in water?
Because they are not polar and so do not attract water molecules.
3 of 36
What do lipids dissolve in?
Alcohol.
4 of 36
What are the three most important lipids in living things?
Triglycerides, phospholipids and steroids.
5 of 36
What is important about the structure of triglycerides, phospholipids and steroids?
They're not polymers, but do have different components bonded together. They're examples of macromolecules.
6 of 36
Triglycerides are made of which two molecules?
One glycerol and three fatty acids.
7 of 36
What are essential fatty acids?
Fatty acids that we cannot make in our bodies - they must be injested complete.
8 of 36
How many carbon atoms does glycerol have?
3.
9 of 36
Why is the fact that glycerol is an alcohol important?
It means it has three free -OH groups, which is important to the structure of triglycerides.
10 of 36
What is a carboxyl group?
A molecule made of one carbon atom, two oxygen atoms and one hydrogen atom. Written -COOH
11 of 36
In fatty acids, where is the carboxyl group attached?
At one end, attached to a hydrocarbon tail.
12 of 36
How many carbons are in the hydrocarbon tail of the fatty acid?
Between 2 and 20.
13 of 36
What makes a fatty acid an acid?
The carboxyl group ionises into H+ ions and a -COO- group. The production of free H+ ions is what makes it an acid.
14 of 36
What makes a fatty acid saturated?
When there are no C=C bonds in the molecule.
15 of 36
What makes a fatty acid unsaturated?
When there is a double bond between carbons meaning fewer hydrogen atoms can be bonded.
16 of 36
What is a monounsaturated fatty acid?
When there is a single C=C bond (e.g. oleic acid)
17 of 36
What is a polyunsaturated fatt acid?
When there is more than one C=C bond (e.g. linoleic acid)
18 of 36
How does being unsaturated affect the shape of a fatty acid?
The double bond gives the molecule a kink, which pushes the molecules apart slightly. This makes them more fluid.
19 of 36
Which type of fatty acids do animal lipids cotain a lot of?
Saturated.
20 of 36
What effect does the double bond have on meltig points?
Saturated fatty acids are solid at 20 degrees celcius whereas the melting point is lower in unsaturated fatty acids.
21 of 36
The -COOH group of the fatty acid and the -OH group of the glycerol bond by which reaction?
A condensation reaction.
22 of 36
What is produced from the condensation reaction and what effect does this have?
A water molecule is produced and the resulting covalent bond is known as an ester bond.
23 of 36
Are the fatty acids in a triglyceride the same or different?
They do not have to be the same, they can be different.
24 of 36
What happens to triglycerides during respiration?
They can be broken down in respiration to release energy and generate ATP.
25 of 36
The first step in respiration of a lipid is hydrolysing the ester bonds: what does this allow to happen?
The glycerol an fatty acids can be broken down completely to carbon dioxide and water.
26 of 36
Is more of less water produced from respiration of a lipid than respiration of a sugar?
More water is produced.
27 of 36
What makes a triglyceride a good energy store?
Because they are insoluble, they can be stored within the cell without affecting the water potential.
28 of 36
In which cells do mammals store fat?
Adipose cells under the skin.
29 of 36
Why does one gram of fat release twice as much energy as one gram of glucose?
Because lipids have a higher proportion of hydrogen atoms than carbohydrates and almost no oxygen atoms.
30 of 36
What function does adipose tissue serve in whales?
It is a storage location of lipids (blubber) but more importantly acts as a heat insulator.
31 of 36
What function do lipids serve in nerve cells?
Lipids act as electrical insulators.
32 of 36
Why is fat iportant to aquatic mammals?
It is less dense than water and so helpsthem float. (Buouancy)
33 of 36
Why do humans have fat around delicate organs?
Acts as a shock absorber.
34 of 36
For which other organism does fat provide protection?
Bacteria. The peptidoglycan cell wall of some in covered in a lipid-rich outer coat.
35 of 36
What type of lipid makes insects and leaves waterproof.
Wax. Waxes are made by combining fatty acids with alcohol molecules much larger than glycerol.
36 of 36

Other cards in this set

Card 2

Front

Lipds contain smaller amounts of which element?

Back

Oxygen

Card 3

Front

Why are lipids insoluble in water?

Back

Preview of the front of card 3

Card 4

Front

What do lipids dissolve in?

Back

Preview of the front of card 4

Card 5

Front

What are the three most important lipids in living things?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules resources »