Basic UK year 9 biology

Everything from nutrition, digestion and the basics on starch, fats and proteins, to the heart and fundamental knowledge on enzymes and circulation

HideShow resource information
  • Created by: Julia
  • Created on: 07-04-12 11:00
Preview of Basic UK year 9 biology

First 339 words of the document:

Holophytic nutrition: typical green plant nutrition ie.
Autotrophic: a self-feeding organism.
Heterotrophic: an organism that feeds on others eg. Humans.
Parasite: an organism that lives in or on a living organism called
the host.
Saprotroph: an organism that feeds on dead or decaying matter
eg. fungi.
Testing for carbohydrates
Starch test:
Use a white tile to drop starch solution into one depression, and a
drop of water in another. To each add one drop of iodine solution
and observe.
POSITIVE: A blue/black colour change
NEGATIVE: No colour change
Reducing sugars (eg. glucose)
Fill half a 250cm3 beaker with warm water an put it on to boil.
Add a 2cm depth of the glucose solution to a clean test tube and
a 2cm depth of distilled water in another.
To each add an equal amount of Benedict's reagent and shake
gently to mix. Place both tubes into the boiling water bath for 2
POSITIVE: A cloudy, brick colour change
NEGATIVE: No colour change
Testing for protein
Add 2cm depth of milk into a test tube and 2cm depth of water as
a control substance in another. To both add 2cm depth of sodium
hydroxide and stir with a glass rod. Add a few drops of copper
sulphate and observe.
POSITIVE: A purple colour change
NEGATIVE: No colour change
Testing for lipids
To a small quantity of the food add a 2cm depth of ethanol. Fats
and oils are not soluble in water.
CAUTION ethanol is highly flammable. Shake the mixture well and
allow to settle.
Slowly decant the liquid into half a test tube of water and
POSITIVE: A milky emulsion
NEGATIVE: No colour change
(Fat comes out of solution as microscopic droplets that scatter
light and produce the `milky' look.)

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

70% of the human body is made up of water.
It cools the body down when it overheats by the water in sweat
It can help flush toxins out of the human body when we are ill.
Water is also a useful means of transport of substances around an
organism's body.
All chemical reactions take place in a watery medium.
The biochemistry of food
CARBOYHYDRATES- contains the chemical elements carbon,
hydrogen and oxygen. They always contain twice as much
hydrogen compared to oxygen.…read more

Page 3

Preview of page 3

Here's a taster:

POLYSACCHARIDES- `many or multiple sugars'
n=large number, often thousands
Starch is found only in plants. It is made up of many glucose
molecules (made in photosynthesis) chemically bonded together.
Unlike sugar, it is not soluble, but is a convenient store or reserve
of glucose ie. Potential energy.
When a plant is in need for more sugar, then chemical bonds can
be broken and the glucose molecules can be used in respiration.…read more

Page 4

Preview of page 4

Here's a taster:

PROTEINS- all very large molecules, which contain the four
elements carbon, hydrogen, oxygen and nitrogen. Can additionally
include iron, sulphur and phosphorus. FeNCHOPS. Used by the
body for growth and repair.
Like polysaccharides, proteins are polymers (long chains made up
of smaller `building block' molecules). Proteins are made up of
many smaller molecules called amino acids.
There are 20 different amino acids, and these can be combined
together in millions of different ways to make millions and
millions of different proteins.…read more

Page 5

Preview of page 5

Here's a taster:

At high temperatures, the complimentary shape of the enzyme's
active site is distorted with heat, as enzymes are proteins. This
means that the substrate is no longer a perfect match, therefore
the enzyme is denatured and will no longer function with the
Beyond optimum temperatures there is so much movement of the
molecules that the enzyme changes shape and the active site
becomes distorted. All enzymes work best at a narrow
temperature range.…read more

Page 6

Preview of page 6

Here's a taster:

Salivary amylase catalyses the breakdown of starch to maltose.
Mechanical breakdown by teeth increases the surface area for
enzyme action and facilitates swallowing.
Muscular waves called peristalsis more the food along the
In the stomach:
Protein Polypeptides
Hydrochloric acid kills bacteria in food and creates the optimum ph
for pepsin.
The bile produced in the liver emulsifies lipids in the duodenum
(top part of small intestines). It is not an enzyme.
The gall bladder stores the bile.…read more

Page 7

Preview of page 7

Here's a taster:

At the centre of the blood system is the heart, it pumps the blood
around the body.
ARTERIES carry blood away from the heart
VEINS carry blood towards the heart
When arteries get to the organs, they branch out into smaller
tubes called capillaries. The capillaries then join up to form veins.
It is in the capillaries that chemicals like oxygen, food and carbon
dioxide pass in and out of the blood.
They are very narrow: a red blood cell can only just squeeze
through.…read more

Page 8

Preview of page 8

Here's a taster:

The blood is often squeezed along by the muscles.
The flow of blood in the veins is helped by valves. They are like
double doors that will only open in one direction; they stop the
blood going backwards as it is moving so slowly.
When the heart is relaxed, both sides fill up with
Blood from the veins.
The atria contracts. The veins also contract where
They join the atria, so blood is forced through the
Ventricles and through the valves.…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »