micro chapter 6

Question 1

Evolution

Answer 1

Major metabolic pathways and cellular structures evolved from early prokaryotic cells

Question 2

Cell structure and Function

Answer 2

Microscopic eukaryotes (e.g., fungi, protozoa, algae) share processes with bacteria but have fundamentally different cellular properties

Question 3

Metabolic Pathways

Answer 3

Bacteria and Archaea exhibit unique metabolic diversity (e.g., nitrogen fixation, methane production, anoxygenic photosynthesis). Microorganisms’ survival depends on their metabolic characteristics

Question 4

Microbial Systems

Answer 4

Microorganisms are ubiquitous, living in diverse ecosystems, and are essential for biogeochemical cycles and microbiota

Question 5

Energy Requirements

Answer 5

All living things need energy from light or chemical reactions, stored as ATP
ATP is used for locomotion, reproduction, nutrient transport, and synthesis of macromolecules

Question 6

ATP structure

Answer 6

ATP consists of an adenosine backbone with three phosphate groups (alpha, beta, gamma).
High-energy bonds between the phosphate groups release energy when broken

Question 7

ATP hydrolysis

Answer 7

ATP hydrolyzes quickly, transferring energy to drive endergonic reactions. The reaction is reversible

ATP + H20 —- ADP + Pi + free energy

Question 8

Fueling Reactions

Answer 8

Produce reducing power in the form of NADH. Biosynthetic pathways use NADPH. ATP and reducing power are often used interchangeably in biological contexts

Question 9

Substrate-level phosphorylation

Answer 9

Organic substrates become phosphorylated without energy input, transferring energy to ADP to form ATP

Question 10

Glycolysis process

Answer 10

Glycolysis splits sugar molecules, transferring energy to ATP. It occurs in two phases:
Phase 1: Consumes 2 ATP (energy in).
Phase 2: Releases energy, producing 2 ATP and 2 NADH (energy out)

Question 11

Fermentation

Answer 11

NADH returns electrons to pyruvate, producing organic acids or alcohols

Question 12

Respiration

Answer 12

Electrons from donor molecules reduce NAD to NADH, generating a proton motive force for ATP production

Question 13

Transmembrane Ion Gradients

Answer 13

Generated during respiration and photosynthesis, these gradients produce more energy but require more time and resources

Question 14

Redox Tower

Answer 14

The hierarchy of electron acceptors affects energy harnessed during respiration. Microbes can utilize various electron acceptors, enhancing metabolic diversity

Question 15

Aerobes

Answer 15

Require oxygen for metabolism and can detoxify reactive oxygen species (ROS)

Question 16

Anaerobes

Answer 16

Do not require oxygen and are generally unable to detoxify ROS

Question 17

Oxygenic Photosynthesis

Answer 17

Involves water as an electron donor, producing oxygen

Question 18

Anoxygenic Photosynthesis

Answer 18

Uses other electron donors and does not produce oxygen

Question 19

Transhydrogenases

Answer 19

convert NADH into NADPH, and ensure there is sufficient NAD+ to receive electrons

Question 20

Chemotrophs

Answer 20

electron moves from high energy level in a chemical molecule (electron donor) to lower energy level in another molecule (electron acceptor) – oxidative

Question 21

Phototrophs

Answer 21

light energy (i.e., photons) excites photosynthetic pigments and moves an electron to a higher energy orbital,