Units 4-7

Question 1

What is kinetic energy?

Answer 1

Energy in motion, such as a moving car.

Question 2

What is potential energy?

Answer 2

Stored energy, such as a stretched rubber band.

Question 3

What is the First Law of Thermodynamics?

Answer 3

Energy cannot be created or destroyed, only transferred or transformed.

Question 4

What is the Second Law of Thermodynamics?

Answer 4

Energy transfer increases entropy (disorder) in the universe.

Question 5

What are endergonic reactions?

Answer 5

Reactions that absorb energy and have positive ΔG.

Question 6

What are exergonic reactions?

Answer 6

Reactions that release energy and have negative ΔG.

Question 7

What is catabolism?

Answer 7

The process that breaks down molecules to release energy.

Question 8

What is anabolism?

Answer 8

The process that builds up molecules using energy.

Question 9

What are enzymes?

Answer 9

Biological catalysts that lower the activation energy of a reaction.

Question 10

What is oxidation?

Answer 10

Involves the loss of electrons.

Question 11

What is reduction?

Answer 11

Involves the gain of electrons.

Question 12

What are the reactants of photosynthesis?

Answer 12

Carbon dioxide (CO₂), water (H₂O), and sunlight.

Question 13

What are light-dependent reactions?

Answer 13

The phase of photosynthesis that occurs in the thylakoid membranes.

Question 14

What is the Calvin cycle?

Answer 14

The light-independent reactions of photosynthesis that occur in the stroma.

Question 15

What is water’s role in photosynthesis?

Answer 15

Water is split in the light-dependent reactions, releasing oxygen (O₂) and providing electrons and protons needed for ATP and NADPH production.

Question 16

What is chlorophyll a?

Answer 16

Absorbs light for photosynthesis.

Question 17

What is chlorophyll b?

Answer 17

Assists in light absorption.

Question 18

What are carotenoids?

Answer 18

Protect against excessive light.

Question 19

What is rubisco?

Answer 19

The enzyme that fixes carbon dioxide in the Calvin cycle.

Question 20

What are autotrophs?

Answer 20

Organisms that produce their own food (e.g., plants).

Question 21

What are heterotrophs?

Answer 21

Organisms that obtain energy by consuming other organisms (e.g., animals).

Question 22

What is the primary usable form of energy in a cell?

Answer 22

ATP (adenosine triphosphate).

Question 23

What are the steps of aerobic cellular respiration?

Answer 23

1) Glycolysis (cytoplasm), 2) Pyruvate oxidation (mitochondrial matrix), 3) Krebs cycle (mitochondrial matrix), 4) Electron transport chain (inner mitochondrial membrane).

Question 24

What is ATP synthase?

Answer 24

Synthesizes ATP by using the energy from proton movement across the mitochondrial membrane.

Question 25

How much ATP is produced in aerobic respiration?

Answer 25

About 36-38 ATP per glucose molecule.

Question 26

What is fermentation?

Answer 26

A process that does not use oxygen and produces less ATP.

Question 27

What are the products of fermentation?

Answer 27

Lactic acid (in animals), ethanol and CO₂ (in yeast).

Question 28

What happens to pyruvic acid in fermentation?

Answer 28

Converted into another product to regenerate NAD⁺ so glycolysis can continue.

Question 29

What is the central dogma of biology?

Answer 29

DNA → RNA → Protein.

Question 30

What are nucleotides?

Answer 30

Made of a phosphate group, a sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base.

Question 31

What are the nitrogenous bases in DNA?

Answer 31

A, T, C, G.

Question 32

What are the nitrogenous bases in RNA?

Answer 32

A, U, C, G.

Question 33

What are Chargaff's Rules?

Answer 33

The amount of A equals T, and the amount of C equals G in a DNA molecule.

Question 34

What is the double-helix structure of DNA?

Answer 34

DNA consists of two strands twisted around each other, with bases paired in the centre.

Question 35

What does antiparallel mean in DNA?

Answer 35

DNA strands run in opposite directions.

Question 36

What does semi-conservative mean in DNA replication?

Answer 36

Each new DNA molecule has one old and one new strand.

Question 37

What are Okazaki fragments?

Answer 37

Short DNA segments on the lagging strand during replication.

Question 38

What are the functions of helicase?

Answer 38

Unwinds DNA.

Question 39

What are the functions of polymerase?

Answer 39

Adds new nucleotides.

Question 40

What are the functions of ligase?

Answer 40

Joins Okazaki fragments.

Question 41

What are telomeres?

Answer 41

Protective end caps of chromosomes.

Question 42

What is telomerase?

Answer 42

Extends telomeres to prevent loss of genetic information.

Question 43

What is PCR?

Answer 43

Used for amplifying DNA sequences for analysis.