Enzymes
What is the main function of an enzyme in a chemical reaction?
Lower the activation energy required for the reaction.
What is the main function of ATP in a cell?
A. To store hereditary information
B. To act as an intermediate energy shuttle that couples reactions
C. To destroy enzymes after reactions
D. To serve as the final electron acceptor in respiration
To act as an intermediate energy shuttle that couples reactions.
Which organism uses light energy and fixes CO₂ to build organic carbon?
A. Chemoheterotroph
B. Photoheterotroph
C. Photoautotroph
D. Chemoautotroph
Photoautotroph.
What is the final electron acceptor in aerobic respiration?
A. CO₂
B. Glucose
C. O₂
D. NADH
O₂
Which group of organisms is classified as prokaryotes?
A. Plants and fungi
B. Bacteria and Archaea
C. Animals and plants
D. Fungi and protists
Bacteria and Archaea.
Give one fact about enzymes and reactions.
(answers may vary) Activation energy requirements get lowered, necessary to sustain life, and/or enzymes are proteins.
What produces about 90% of the ATP during cellular respiration?
A. Glycolysis
B. Pyruvate oxidation
C. Citric acid cycle
D. ETC and chemiosmosis
ETC and chemiosmosis.
Which of the following correctly describes a photoautotroph?
A.Uses light for energy and CO₂ as its carbon source.
B.Uses chemicals for energy and organic molecules as its carbon source.
C.Uses light for energy and organic molecules as its carbon source.
D.Uses chemicals for energy and CO₂ as its carbon source.
Uses light for energy and CO₂ as its carbon source.
What is one major difference between prokaryotic and eukaryotic cells?
A. Prokaryotes have a nucleus, but eukaryotes do not.
B. Eukaryotes have a membrane-bound nucleus, but prokaryotes do not.
C. Both always have membrane-bound organelles.
D. Prokaryotes are always larger than eukaryotes.
Eukaryotes have a membrane-bound nucleus, but prokaryotes do not.
According to the First Law of Thermodynamics, what happens to energy?
A. Energy is created during respiration.
B. Energy is destroyed when heat is released.
C. Energy can be transferred or transformed but not created or destroyed.
D. All energy eventually becomes ATP.
Energy can be transferred or transformed but not created or destroyed.
Which statement about enzymes is correct?
A. Enzymes change ΔG
B. Enzymes are consumed after one reaction
C. Enzymes are specific and reusable
D. Enzymes always slow reactions down
Enzymes are specific and reusable.
What is the net ATP yield from glycolysis per glucose molecule?
A. 1 ATP
B. 2 ATP
C. 4 ATP
D. 30–32 ATP
2 ATP.
Which type of microorganism cannot survive in oxygen?
A. Obligate aerobe
B. Facultative anaerobe
C. Obligate anaerobe
D. Photoautotroph
Obligate anaerobe.
Where does glycolysis occur?
A. Nucleus
B. Cytosol
C. Inner mitochondrial membrane
D. Golgi apparatus
Cytosol.
Why does energy decrease as you move up a trophic pyramid?
A.Energy is completely recycled between organisms.
B.Organisms create new energy at each trophic level.
C.Much of the energy is lost as heat during energy conversions.
D.Higher trophic levels do not require energy.
Much of the energy is lost as heat during energy conversions.
How do enzymes speed up chemical reactions?
A. By increasing the reaction's overall free energy change
B. By permanently changing the products
C. By raising the activation energy required
D. By being consumed during the reaction
Trick answer! If you knew this well, you would notice the answer isn't here, it LOWERS activation energy rather than raising it.
Which type of membrane transport requires ATP and moves substances from low concentration to high concentration?
A.Simple diffusion.
B.Facilitated diffusion.
C.Osmosis.
D.Active transport.
Active transport.
Which statement best describes catabolic pathways?
A. They build complex molecules using energy.
B. They break down complex molecules and release energy.
C. They stop all chemical reactions in a cell.
D. They store genetic information.
They break down complex molecules and release energy.
What is the main purpose of fermentation?
A. Produce large amounts of ATP
B. Regenerate NAD⁺ so glycolysis can continue
C. Produce oxygen
D. Break down proteins
Regenerate NAD⁺ so glycolysis can continue.
How do covalent bonds work in balancing?
a.They share electrons to balance the amount of electrons in each cloud and satisfy the target amount of electrons atoms seek.
b.One completely transfers some electrons to another, satisfying one and sometimes satisfying the one that does the full transfer.
c.One atom shares protons to another to balance out the equilibrium and make them both neutral.
d.Naturally negative atoms gain more electrons to balance out and reach a higher balancing point, while positive ones share their electrons.
They share electrons to balance the amount of electrons in each cloud and satisfy the target amount of electrons atoms seek.
List 3 functions of enzymes in the human body.
(Answers may vary)Digestion, DNA replication/repair, detoxification, cellular respiration.
Which process has the lowest ATP yield?
A. Aerobic respiration
B. Anaerobic respiration
C. Fermentation
D. Photosynthesis
Fermentation.
Which statement correctly distinguishes fermentation from anaerobic respiration?
A. Both always require oxygen.
B. Fermentation uses an organic molecule as the electron acceptor and produces ATP through substrate-level phosphorylation.
C. Anaerobic respiration does not use an electron transport chain.
D. Fermentation produces more ATP than aerobic respiration.
Fermentation uses an organic molecule as the electron acceptor and produces ATP through substrate-level phosphorylation.
What happens to water during osmosis when a microbe is placed in a high-solute environment?
A. Water enters the cell
B. Water leaves the cell
C. No water moves
D. The cell immediately divides
Water leaves the cell.
What is the second law of defying entropy through solar influx?
A.Energy cannot be created or destroyed. Life depends on a continuous solar influx.
B.Energy conversions proceed in any direction which decreases overall entropy. Heat is continuously gained.
C.Energy conversions proceed in a direction which increases overall entropy. Heat is continuously lost as unrecoverable heat.
D.Energy must be created or destroyed. Life only somewhat depends on the continuous solar influx.
Energy conversions proceed in a direction which increases overall entropy. Heat is continuously lost as unrecoverable heat.