Question

37) Transcription factors sit on DNA switches and call in _____________________________ so that a gene is transcribed (turned on).
        A. DNA polymerase    B. repressors    C. helicase    D. RNA polymerase           

38) In DNA replication, two new strands of DNA molecules grow as bases are added by which enzyme?
A. Bacterial duplicating complex            B. DNA polymerase
C. DNA replicase                    D. RNA polymerase

39) The role of enzymes is
    A. to move particles against the concentration gradient.
    B. to lower the activation energy of reactions.
    C. to release energy by hydrolyzing ATP.
    D. to act as an electron carrier.

40) In aerobic cellular respiration, what is the path of the electron’s movement?
    A. chemical bonds of glucose to NADH to O2
    B. NADH to CO2 to H20
    C. H20 to FADH to glucose
    D. chemical bonds of glucose to NADH to ATP synthase

Answer 1

Ans-37)d) RNA polymerase

Explaination:tramscription factors are proteins that regulate transcription and they call RNA polymerase to bind on DNA strand.RNA polymerase  start the transcription using DNA as template strand and results in expression of genes .

Ans-38)DNA polymerase

Explaination: DNA polymerase is the enzyme that added bases to the ist carbon of deoxyribose through glycosidic bond during DNA replication.

Ans-39)b) to lower the activation energy of reaction.

Explaination: enzyme increases the rate of reaction by decreasing the activation energy.

Ans-40)Chemical bonds of glucose to NADH to O2.

Explaination : in glycolysis glucose converts into pyruvate which convert into acety coA by pyruvate dehyrogenase and acetyl coA enters kreb cycle. In both glycolysis and kreb cycle

NADH are produced and they oxidised to provide electron to oxygen. Oxygen is the final acceptor of electron Electron transport chain.