Question
(a) (i) Label a peptide bond in the diagram of a polypeptide.
(ii) Outline the primary structure of proteins.
(b) Identify two hydrolysis reactions that occur in the small intestine.
Answer/Explanation
Ans: a (i)
a (ii) number/sequence/order of amino acids «in a protein/polypeptide chain»
b)
a. polysaccharides to disaccharides/monosaccharides
OR
starch/glycogen to maltose
b. sucrose to glucose AND fructose
c. maltose to glucose
d. lactose to glucose AND galactose
e. proteins/peptides/polypeptides to shorter peptides/amino acids
OR
dipeptides to amino acids
Question
(a) State one similarity and one difference between the structure of genes and short tandem repeats.
Similarity:
Difference:
(b) Outline the role of short tandem repeats in DNA profiling.
Answer/Explanation
Ans:
a)
similarity: both made of DNA/nucleotides
OR
both have bases/adenine/cytosine/guanine/thymine
OR
neither has uracil
difference: genes are longer/have longer DNA/base sequences «without repeats»
OR
genes have introns/exons but tandem repeats do not
OR
genes have base sequences that code for polypeptides/proteins and tandem repeats do not
b)
a. tandem repeats allow individuals to be distinguished/compared/identified OR tandem repeats are used to identify the source of a DNA sample
b. unique/different number of repeats/combination of tandem repeats in each individual OR unique/different pattern of bands in each individual
c. PCR used for copying/amplifying «tandem repeats»
d. gel electrophoresis used for separation «of tandem repeats»/create pattern of bands