Grade 12 Biochemistry Test Review
Graded A+
In which organelle does the majority of ATP production occur during cellular respiration?
✔✔ Mitochondria
What is the significance of the R-group (side chain) in an amino acid?
✔✔ The R-group determines the unique properties and functions of each amino acid.
What happens when a protein denatures?
✔✔ The protein loses its three-dimensional structure and can no longer function properly.
How does a phospholipid's structure make it ideal for forming cell membranes?
✔✔ Its hydrophilic head and hydrophobic tail allow it to form a bilayer, creating a barrier
between the cell's interior and exterior.
What is the difference between anabolism and catabolism in metabolism?
✔✔ Anabolism involves building complex molecules from simpler ones, while catabolism
breaks down complex molecules into simpler ones to release energy.
1
,How do buffers help maintain pH in biological systems?
✔✔ Buffers resist changes in pH by neutralizing small amounts of acids or bases.
Why are some amino acids termed "essential" in human nutrition?
✔✔ Essential amino acids cannot be synthesized by the body and must be obtained through the
diet.
What is the role of hydrogen bonds in the secondary structure of proteins?
✔✔ Hydrogen bonds stabilize the folding of proteins into alpha-helices and beta-sheets.
In terms of enzyme kinetics, what happens at Vmax?
✔✔ At Vmax, the enzyme is working at its maximum rate, and all active sites are fully occupied
by substrates.
How do cofactors and coenzymes assist enzyme function?
✔✔ Cofactors and coenzymes help enzymes catalyze reactions by stabilizing substrate binding
or participating in the reaction.
2
, How does pH affect enzyme activity?
✔✔ Extreme pH levels can denature enzymes or alter their activity, disrupting their ability to
bind with substrates.
What role do disulfide bonds play in protein structure?
✔✔ Disulfide bonds help stabilize the tertiary structure of proteins by linking different parts of
the polypeptide chain.
Why is feedback inhibition important in biochemical pathways?
✔✔ Feedback inhibition prevents the overproduction of products by regulating the activity of
enzymes in metabolic pathways.
In what way do isotopes of the same element differ?
✔✔ Isotopes differ in the number of neutrons in their nuclei, which affects their atomic mass but
not their chemical properties.
How do nonpolar molecules typically behave in water?
3
Graded A+
In which organelle does the majority of ATP production occur during cellular respiration?
✔✔ Mitochondria
What is the significance of the R-group (side chain) in an amino acid?
✔✔ The R-group determines the unique properties and functions of each amino acid.
What happens when a protein denatures?
✔✔ The protein loses its three-dimensional structure and can no longer function properly.
How does a phospholipid's structure make it ideal for forming cell membranes?
✔✔ Its hydrophilic head and hydrophobic tail allow it to form a bilayer, creating a barrier
between the cell's interior and exterior.
What is the difference between anabolism and catabolism in metabolism?
✔✔ Anabolism involves building complex molecules from simpler ones, while catabolism
breaks down complex molecules into simpler ones to release energy.
1
,How do buffers help maintain pH in biological systems?
✔✔ Buffers resist changes in pH by neutralizing small amounts of acids or bases.
Why are some amino acids termed "essential" in human nutrition?
✔✔ Essential amino acids cannot be synthesized by the body and must be obtained through the
diet.
What is the role of hydrogen bonds in the secondary structure of proteins?
✔✔ Hydrogen bonds stabilize the folding of proteins into alpha-helices and beta-sheets.
In terms of enzyme kinetics, what happens at Vmax?
✔✔ At Vmax, the enzyme is working at its maximum rate, and all active sites are fully occupied
by substrates.
How do cofactors and coenzymes assist enzyme function?
✔✔ Cofactors and coenzymes help enzymes catalyze reactions by stabilizing substrate binding
or participating in the reaction.
2
, How does pH affect enzyme activity?
✔✔ Extreme pH levels can denature enzymes or alter their activity, disrupting their ability to
bind with substrates.
What role do disulfide bonds play in protein structure?
✔✔ Disulfide bonds help stabilize the tertiary structure of proteins by linking different parts of
the polypeptide chain.
Why is feedback inhibition important in biochemical pathways?
✔✔ Feedback inhibition prevents the overproduction of products by regulating the activity of
enzymes in metabolic pathways.
In what way do isotopes of the same element differ?
✔✔ Isotopes differ in the number of neutrons in their nuclei, which affects their atomic mass but
not their chemical properties.
How do nonpolar molecules typically behave in water?
3
