Paper 1 silly mistakes

Explain one way in which starch molecules are adapted for their function in plant cells (2)

1. Insoluble;

2. Don’t affect water potential;

   OR

3. Helical;

4. Compact;

   OR

5. Large molecule;

6. Cannot leave cell;

Explain how cellulose molecules are adapted for their function in plant cells (3)

1. long and straight chains

2. become linked together by many hydrogen bonds to form myofibrils

3. provide strength to cell wall

Contrast the processes of facilitated diffusion and active transport (3)

1. fac.diff. involves channel proteins and carrier proteins vs a.t. only involves carrier proteins

2. fac.diff. is passive vs a.t. uses ATP

3. fac.diff. happens down a concentration gradient vs a.t. occurs against a concentration gradient

.

.

Give the two types of molecule from which a ribosome is formed (1)

• RNA

• protein/amino acid

Define species richness (1)

The number of species in a community

accept habitat/ecosystem/environment

anything other than population!!!!

Draw structure of amino acid (1)

Some people eat red meat for many years without having any reaction, then have an allergic reaction to the alpha-gal in red meat.

An allergic reaction is caused by an immune response.

Draw a labelled diagram of an antibody and identify the specific alpha-gal binding site (3)

• Y shape showing two long and two short (polypeptide) chains correctly positioned;

• (Alpha-gal) binding site labelled on the end of the branches of the Y of the antibody;

• Variable region labelled

  OR Constant region labelled

  OR Disulfide bridge/bond labelled;