Theme 2 - Part B Flashcards Preview

Biology 241 > Theme 2 - Part B > Flashcards

Flashcards in Theme 2 - Part B Deck (21):
1

What ancient pathway is part of aerobic respiration, fermentation AND anaerobic respiration? Where in the cell does it occur?

Glycolysis; in the cytosol

2

What is the net ATP production in glycolysis?

2 ATP (2 initially invested, 4 produced)

3

At the conclusion of glycolysis, in what molecule(s) is most of the energy from glucose contained?

pyruvate

4

Describe the process of substrate-level phosphorylation. In which steps of cellular respiration does it occur?

phosphate group from a high-energy substrate molecule is transferred to ADP, producing ATP. This process is mediated by an enzyme.
Occurs in glycolysis and the citric acid (Krebs) cycle.

5

What is the effect of a competitive and non-competitive inhibitor on enzyme kinetics (Km and Vmax)?

competitive: increased Km; Vmax is unchanged.
non-competitive: decreased Vmax; Km is unchanged.

6

Through what type of transport is pyruvate transported from the cytosol to the inter-membrane space? From there to the matrix?

Transported through facilitated diffusion to the inter-membrane space;
transported through secondary active transport to the matrix

7

In which steps of cellular respiration is carbon dioxide produced?

Pyruvate oxidation and citric acid cycle

8

What are the products of one turn of the citric acid cycle?

2CO2; 3NADH; FADH2; ATP

9

The electron transport chain consists of 4 protein complexes; which is a single peripheral membrane protein?

Complex II

10

Electron flow from one complex to the next is facilitated by two mobile electron shuttles; which ones?

Ubiquinone: hydrophobic molecule found in core of membrane; shuttles e- from complexes I and II to complex III.

Cytochrome c: located in the inter-membrane space side of membrane; shuttles e- from complex III to complex IV.

11

What are prosthetic groups, and what role do they play in the electron transport chain?

The are redox-reactive cofactors that alternate between reduced and oxidized states, accepting e- from upstream molecules and donating e- downstream.
They are arranged from high to low free energy (and increasing affinity for e-), allowing sequential and spontaneous e- movement down the ETC.

12

Which components of the ETC pump protons into the inter-membrane space?

Complex I, Ubiquinone and Complex IV

13

What is the final electron acceptor in aerobic respiration?

O2

14

What is proton-motive force?

The combination of H+ concentration gradient and voltage difference across the membrane produces stored energy known as PMF

15

What is the process of harnessing PMF to do work referred to?

chemiosmosis

16

What is oxidative phosphorylation?

Oxidative phosphorylation is ATP synthesis that is linked to oxidation of high-energy molecules in an ETC. It harnesses the proton-motive force resulting from the ETC to drive the production of ATP by a protein called ATP synthase.

17

What lines of evidence support endosymbiosis?

1. Morphology: form/shape of mitochondria and chloroplasts is similar to bacteria & archaea.
2. Reproduction: mitochondria and chloroplasts derived only from pre-existing mit&chlor. Both divide through binary fission, similar to bacteria & archaea.
3. Mitochondria & chloroplasts contain their own DNA (which is circular, like bacteria & archaea).
4. Mitochondria and chloroplasts contain complete transcription & translation machinery.
5. Both have ETCs.
6. Sequencing RNA of mitochondria & chloroplasts establishes that they belong on bacterial branch of tree of life.

18

How do obligate anaerobes produce ATP?

fermentation

19

What are the advantages of living in extreme organisms (e.g. snottites in Cueva de Villa Luz)?

less competition, fewer predators, and ability to exploit the available resources

20

What are the advantages of growth within biofilms?

protect organisms inside (e.g. regulate pH); concentrate resources

21

How do fermentation pathways allow glycolysis to continue?

They convert NADH to NAD+, allowing the electron carrier to cycle back to glycolysis.