Biology AS AQA Unit 2 The Variety of Life

Made these notes for my year 12 summer exam to revise and read over. There are spelling mistakes in most of my files but due to the busy exam schedule I had no time to correct them (sorry).

Most files have more information than what is needed but I feel it helps you feel more confident walking into the exam if you have a greater knowledge background and may help when having to apply knowledge to questions. Good luck :)

HideShow resource information
  • Created by: Chelcie
  • Created on: 02-09-13 12:51

Pages in this set

Page 1

Preview of page 1
The Variety of Life
HAEMOGLOBIN MOLECULES

PRIMARY STRUCTURE
Consisting of 4 polypeptide chains.

SECONDARY STRUCTURE
Polypeptide chains are coiled into a helix.

TERTIARY STRUCTURE
Polypeptides are folded into a precise shape-
importantly to carry O

QUATERNY STRUCTURE
All polypeptides are linked to form a spherical
molecule.
Each polypeptide is associated…

Page 2

Preview of page 2
WHY DO DIFFERENT HAEMOGLOBINS HAVE DIFFERENT AFFINITIES?
Different haemoglobin have different sequences of amino acids and therefore shapes. Its affinity
for O depends on the shape.

LOADING/ASSOCIATING
When haemoglobin combines with O in lungs

UNLOADING/DISSOCIATING
When haemoglobin releases O at tissues


OXYGEN DISSOCIATION CURVES
At low partial pressure of oxygen,…

Page 3

Preview of page 3
LOADING, TRANSPORT, UNLOADING OF O
At gas exchange surface, pH is high due to the low levels of CO
The higher the pH changes, the higher affinity of O. This is due to a shape change to enable
ready loading of O so that it is not able to easily…

Page 4

Preview of page 4
STARCH
Polysaccharide
Chains of a-glucose monosaccharides linked by glycosidic bonds that are formed in
condensation reactions.
Wound into a coil to make more compact.
Starch is a good energy store because:
It is insoluble so it doesn't draw water into the cell by osmosis
Compact
When hydrolysed it forms a-glucose…

Page 5

Preview of page 5
Chloroplast envelope:
Double plasma membrane that surrounds the organelles. Highly selective to what enters/leaves
chloroplast.

Grana:
Stacks up to 100 thylakoids (disc like structures) where 1st stage of photosynthesis occurs.

Chlorophyll:
Has photosynthesis pigment. Found within thylakoids.

Some thylakoids have tubular extensions that join with thylakoids in adjacent Grana.

Adaption:…

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »