Practice Q

Question 1

Give two types of molecules from which a ribosome is made

Answer 1

1. RNA/rRNA;
2. Protein;

Question 1

Give four structural differences between a DNA molecule and a mRNA molecule

Answer 1

1. DNA has deoxyribose, mRNA has ribose;
2. DNA has thymine, mRNA has uracil;
3. DNA long, mRNA short;
4. DNA is double stranded, mRNA is single stranded;
5. DNA has hydrogen bonds, mRNA has no hydrogen bonds

6.DNA has (complementary) base pairing,
mRNA does not;

Question 2

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

Answer 2

1. Condensation reaction between amino acids;
2. (Forming) peptide bonds;
3. Creating (specific) sequence/order of amino acids;

Question 3

Describe one similarity and one difference between the induced-fit model of enzyme action and the lock and key model of enzyme action.

Answer 3

(Similarity)
1. Substrate fits/binds to active site and
Enzyme-substrate complex (formed);

(Difference)
2. Active site changes shape, but does not change in lock and key

(Initially) active site not complementary to substrate with induced-fit, but is
complementary in lock and key;

Question 4

State how enzymes help reactions to proceed quickly at lower temperatures.
Do not write about active sites in your answer.

Answer 4

Lower/reduce activation energy (needed to start a reaction);