A-Level Biology Induction Assessment 2023

Question 1

Eukaryotic cells produce and release proteins
Outline the role of organelles in the production, transport and release of proteins from eukaryotic cells
Do not include details of transcription and translation in your answer

Answer 1

DNA in nucleus is code for protein
Ribosomes produce proteins
Mitochondria produce ATP for protein synthesis
Golgi apparatus package proteins

Question 2

The image below is a transmission electron micrograph of a plant cell

Suggest why a nucleus is not visible in above image

Name the organelles labelled S and T in the image above

Answer 2

Nucleus not stained

Organelle S = Vacuole
Organelle T = Chloroplast

Question 3

Describe how a peptide bond is formed between two amino acids to form a dipeptide

Answer 3

Condensation reaction between amine and carboxyl

Question 4

The secondary structure of a polypeptide is produced by bonds between amino acids

Describe how.

Answer 4

Hydrogen bonds between NH group and C -_ group forming beta pleated sheets or alpha helices

Question 5

Two proteins have the same number and type of amino acids but different tertiary structures

Explain why.

Answer 5

Different primary structure
Forms ionic/hydrogen/ disulphide bridges in different places

Question 6

Describe the structure and function of the nucleus

Answer 6

Structure: Nuclear envelope and pores
Chromosomes
Function: stores genetic information for polypeptide production
DNA replication
Transcription occurs
Production of ribosomes

Question 7

Describe the structure of proteins

Answer 7

Polymer of amino acids
Joined by peptide bonds
Formed by condensation reactions
Primary structure is order of amino acids
Secondary structure is folding of polypeptide chain due to hydrogen bonding

Question 8

A dipeptide consists of two amino acids joined by a peptide bond.
Dipeptides may differ in the type of amino acids they contain

Describe two other ways in which all dipeptides are similar and one way they might differ

Answer 8

Similarities: NH2
COOH
Difference: R groups

Question 9

Describe how monomers join to form the primary structure of a protein

Answer 9

Join by a condensation reaction
Forming peptide bonds
Creating sequence of amino acids

Question 10

The number of amino acids in the beta chains in figure 2 is 3.546% greater than in the alpha chains. Each alpha chain contains 141 amino acids

Calculate how many amino acids that there are in total in the haemoglobin molecule shown in figure 2. Give your answer to the nearest whole number

Answer 10

141/100 =141 X 3.546 = 5
141 + 5 = 146
146 + 146 + 141 + 141 = 574