Question

which set of membrane proteins in the figure depicts the transport of solute molecules across the membrane?
a
b
c
d
53.
part a
which of the following does not describe enzymes?
each enzyme is chemically specific.
some enzymes are purely protein.
enzymes work by raising the energy of activation.
some enzymes are protein plus a cofactor.
54.
part a
what is a chain of more than 50 amino acids called?
nucleic acid
protein
triglyceride
polysaccharide

Explanation:

Question 52 (Membrane Protein Transport)

Step1: Analyze each option

• Option A: Shows proteins (one with a channel, one using ATP) moving solute across the membrane (arrows indicate solute movement through/by the proteins).
• Option B: Appears to be a vesicle or something related to membrane fusion/endocytosis/exocytosis, not direct solute transport across the membrane.
• Option C: Shows proteins but the arrows seem to be about molecules around, not clear solute transport across the membrane.
• Option D: Shows proteins but the interaction looks like protein - protein or something else, not solute transport across the membrane.

Step2: Determine the correct option

Based on the analysis, Option A depicts the transport of solute molecules across the membrane as it has proteins (channel and ATP - driven) with solute movement across the membrane.

Enzymes lower the energy of activation (activation energy) to speed up reactions. The option "Enzymes work by raising the energy of activation" is incorrect as it contradicts the function of enzymes. Other options: enzymes are chemically specific, some are purely protein, some have a protein plus a cofactor, which are correct descriptions.

• Nucleic acids are made of nucleotides, not amino acids.
• Proteins are made of amino acids, and a chain of more than 50 amino acids is a protein.
• Triglycerides are made of glycerol and fatty acids.
• Polysaccharides are made of monosaccharides.

Answer:

A

Question 53 (Enzymes)