Grade 12 Biology Exam Review
Questions and Already Passed
Answers 2025-2026 Updated.
Dehydration synthesis - Answer A reaction at which two molecules combine to create a
larger molecule taking out H2O.
Hydrolysis - Answer A reaction at which a compound reacts with water to produce other
compounds.
Redox - Answer A chemical reaction where atoms gain or lose electrons (LEO the lion says
GER)
Neutralization reaction - Answer Where an acid and a base reacts to form H2O.
Lipids - Answer Made out of carbon, hydrogen and oxygen. The role of the lipids is to
insulate the organs and joints. The are made up of ester bonds.
Protein - Answer Made out of amino acids and bonds are peptide bonds, the protein form
enzymes, cell surface markers and cell membrane are protein channels.
Carbohydrates - Answer Made up of hydrogen, carbon and oxygen, it is the main source of
energy, and the bonds are glycosidic linkages.
[->types of carbs= Monosaccharide= one sugar, Disaccharide= 2 sugars, Polysaccharide= many
sugars (3 or more).]
Nucleic Acid - Answer Organisms store hereditary and genetic information that determine
structural and functional characteristic.
Enzymes - Answer Lower activation energy and are catalyst. Factors affecting the reactions
are temperature, ph, and concentration.
(Enzyme shape) = Non-competitive- Does not compete for an active site.
= Competitive- Able to enter active site to block normal substrate for
, Pyruvate Oxidation - Answer This occurs in the mitochondrial matrix 2 pyruvate and a NAD
forms 2 NADH ,2 CO2 and 2 acetyl coa
Krebs - Answer Happens in mitochondrial matrix. 3 NADPH is made, 2 CO2 is made, 1 FADH
is made, and 1 ATP is made.
Oxidative phosphorylation - Answer Involves a series of redox reaction, O2 is used to oxidize
electron carriers FADH and NADH to produce ATP.
ETC - Answer Happens in the inner mitochondrial membrane, and involves use of high
energy to push H+ from the stroma to the inner Thylakoid space.
Chloroplast - Answer Found mainly in the cell of the mesophyll (interior tissue of the leaf).
Within the chloroplast you have the thylakoid, granum, and stroma.
Light dependent - Answer Occurs in the thylakoid and uses H2O and light to produce ATP,
NADH and O2.
Calvin Cycle - Answer Occurs in the stroma and uses carbon dioxide, ATP and NADH to
produce sugar.
Photosynthesis - Answer Occurs in plants, leafs are the major location of photosynthesis.
CO2 enters and O2 exits the leaf through small holes called stomata.
Substrate Leve - Answer ATP is formed directly in a catalyst reaction for each glucose
molecule made 4 ATP are generated.
Oxidative Phosphorylation - Answer ATP is formed indirectly and involves a series of redox
reaction. The use of O2 to oxidize electron carriers NADH and FADH to produce ATP.
DNA - Answer Stays within the nucleus and is a double helix shape, A pairs with T.
RNA - Answer Leaves the nucleus and is single stranded, T pairs with uracil (u).
Questions and Already Passed
Answers 2025-2026 Updated.
Dehydration synthesis - Answer A reaction at which two molecules combine to create a
larger molecule taking out H2O.
Hydrolysis - Answer A reaction at which a compound reacts with water to produce other
compounds.
Redox - Answer A chemical reaction where atoms gain or lose electrons (LEO the lion says
GER)
Neutralization reaction - Answer Where an acid and a base reacts to form H2O.
Lipids - Answer Made out of carbon, hydrogen and oxygen. The role of the lipids is to
insulate the organs and joints. The are made up of ester bonds.
Protein - Answer Made out of amino acids and bonds are peptide bonds, the protein form
enzymes, cell surface markers and cell membrane are protein channels.
Carbohydrates - Answer Made up of hydrogen, carbon and oxygen, it is the main source of
energy, and the bonds are glycosidic linkages.
[->types of carbs= Monosaccharide= one sugar, Disaccharide= 2 sugars, Polysaccharide= many
sugars (3 or more).]
Nucleic Acid - Answer Organisms store hereditary and genetic information that determine
structural and functional characteristic.
Enzymes - Answer Lower activation energy and are catalyst. Factors affecting the reactions
are temperature, ph, and concentration.
(Enzyme shape) = Non-competitive- Does not compete for an active site.
= Competitive- Able to enter active site to block normal substrate for
, Pyruvate Oxidation - Answer This occurs in the mitochondrial matrix 2 pyruvate and a NAD
forms 2 NADH ,2 CO2 and 2 acetyl coa
Krebs - Answer Happens in mitochondrial matrix. 3 NADPH is made, 2 CO2 is made, 1 FADH
is made, and 1 ATP is made.
Oxidative phosphorylation - Answer Involves a series of redox reaction, O2 is used to oxidize
electron carriers FADH and NADH to produce ATP.
ETC - Answer Happens in the inner mitochondrial membrane, and involves use of high
energy to push H+ from the stroma to the inner Thylakoid space.
Chloroplast - Answer Found mainly in the cell of the mesophyll (interior tissue of the leaf).
Within the chloroplast you have the thylakoid, granum, and stroma.
Light dependent - Answer Occurs in the thylakoid and uses H2O and light to produce ATP,
NADH and O2.
Calvin Cycle - Answer Occurs in the stroma and uses carbon dioxide, ATP and NADH to
produce sugar.
Photosynthesis - Answer Occurs in plants, leafs are the major location of photosynthesis.
CO2 enters and O2 exits the leaf through small holes called stomata.
Substrate Leve - Answer ATP is formed directly in a catalyst reaction for each glucose
molecule made 4 ATP are generated.
Oxidative Phosphorylation - Answer ATP is formed indirectly and involves a series of redox
reaction. The use of O2 to oxidize electron carriers NADH and FADH to produce ATP.
DNA - Answer Stays within the nucleus and is a double helix shape, A pairs with T.
RNA - Answer Leaves the nucleus and is single stranded, T pairs with uracil (u).
