PROTEIN SYNTHESIS

Question 1

KEY PROTEIN FUNCTIONS

Answer 1

• binding (transport + storage, membrane channels, receptors + defence)
• catalysis (chemical reactions)
• switching (hormones, transcription factors)
• structure + motion (muscle fibres)

Question 2

PROTEIN SYNTHESIS

Answer 2

• DNA of each cell holds complete set of instructions for cellular protein synthesis
• one gene codes for one unique protein

Question 3

DNA

Answer 3

• structure provides instructions for protein synthesis
• double stranded chain of nucleic acid
• twisted to form double helix
• 1 coding + 1 template strand
• chain consisting of polymer of nucleotides (building blocks of nucleic acid)

Question 4

DNA STRUCTURE

Answer 4

• sugar
• phosphate
• nitrogenous base
• 2 strands antiparallel (3-5, 5-3)
• 4 base pairs (G-C, A-T)

Question 5

TRANSCRIPTION

Answer 5

• DNA passes on instructions to cytoplasm by synthesising mRNA with copy of code for protein required
• takes place in nucleus
• to copy code, base sequence of DNA coding strand must be replicated
• can only attract complementary base so to form mRNA with correct code uses template strand

Question 6

TRANSLATION

Answer 6

mRNA directs the building of the protein