LESSON 2

Question 1

The capacity to do work or produce heat; can change forms but cannot be created or destroyed.

Answer 1

Energy

Question 2

The cell’s main energy currency; provides energy for most energy-consuming activities.

Answer 2

ATP (Adenosine Triphosphate)

Question 3

Process where ATP + H₂O → ADP + Pi; releases energy for cellular reactions.

Answer 3

ATP Hydrolysis

Question 4

ADP + Pi → ATP + H₂O; occurs in cytosol (glycolysis), mitochondria (cellular respiration), and chloroplasts (photosynthesis).

Answer 4

ATP Synthesis

Question 5

Powers: protein synthesis, DNA/RNA synthesis, polysaccharide & fat synthesis, nerve impulses, active transport, osmosis, phosphorylation, muscle contraction, cilia/flagella movement, and bioluminescence.

Answer 5

ATP Consumption

Question 6

In mammals, ATP is also used for inflammation, oxygen sensing, taste signaling, and bladder emptying signals.

Answer 6

Extracellular ATP

Question 7

Proposed by Dr. Lynn Margulis (1967). States that mitochondria and chloroplasts originated from prokaryotic cells engulfed by early eukaryotes, forming a symbiotic relationship.

Answer 7

Endosymbiont Theory

Question 8

Evidence of the Endosymbiont Theory

Answer 8

1. Double membranes in mitochondria and chloroplasts.
2. Own circular DNA and ribosomes like prokaryotes.
3. Autonomous growth and reproduction.

Question 9

Sites of cellular respiration — convert glucose, fats, and oxygen into ATP. Most numerous in muscle and liver cells where energy demand is high.

Answer 9

Mitochondria

Question 10

Selectively permeable; contains proteins and pores for transporting molecules.

Answer 10

Outer Membrane of Mitochondria

Question 11

Highly folded into cristae to increase surface area for ATP production; houses ETC (electron transport chain) and ATP synthase.

Answer 11

Inner Membrane of Mitochondria

Question 12

Space between outer and inner membranes; important in ATP production.

Answer 12

Intermembrane Space of Mitochondria

Question 13

Innermost part; contains enzymes, ribosomes, and mitochondrial DNA for energy production.

Answer 13

Matrix

Question 14

Found in plants & algae; convert solar energy into chemical energy (sugars) via photosynthesis.

Answer 14

Chloroplasts

Question 15

Semi-permeable; allows small molecules and ions to pass.

Answer 15

Outer Membrane of Chloroplasts

Question 16

Controls material passage; also synthesizes fatty acids, lipids, and carotenoids.

Answer 16

Inner Membrane of Chloroplasts

Question 17

Thin space (10–20 nm) between outer and inner membranes.

Answer 17

Intermembrane Space of Chloroplasts

Question 18

Fluid inside the inner membrane; contains DNA, ribosomes, starch granules, enzymes; site of Calvin cycle.

Answer 18

Stroma

Question 19

Membranous sacs where light reactions of photosynthesis occur; contains chlorophyll.

Answer 19

Thylakoid System

Question 20

Stacks of thylakoids (10–20 per stack) to maximize light capture.

Answer 20

Grana

Question 21

in contact with the stroma and are in the
form of helicoid sheets; contain Photosystem I and ATP synthase.

Answer 21

Stromal Thylakoids

Question 22

Contain Photosystem II; tightly stacked for efficient light absorption.

Answer 22

Granal Thylakoids

Question 23

Protein complexes in thylakoid membranes that harvest light energy and excite electrons for ATP production.

Answer 23

Photosystem I & II

Question 24

Large protein complex in thylakoid membranes that produces ATP during photosynthesis.

Answer 24

ATP Synthase (Chloroplast)

Question 25

Double-membrane organelles in plants/algae; manufacture and store compounds.

Answer 25

Plastids

Question 26

Store starch (amylose), especially in roots & tubers.

Answer 26

Amyloplasts

Question 27

Contain pigments giving fruits and flowers their orange/yellow colors.

Answer 27

Chromoplasts

Question 28

A metabolic process that uses oxygen to drive

Answer 28

Cellular respiration