W3-lecture 2: Metabolism and energy

Question 1

T or F: most of the cell’s NADPH will be produced by the pentose phosphate pathway

Answer 1

T

Question 2

What are the two roles of the pentose phosphate pathway?

Answer 2

To produce NADPH and also to produce sugars that the cell will need (example malate used by the TCA cycle). So the pentose phosphate pathway is an anapleurotic pathway.

Question 3

T or F : the pentose phosphate pathway occurs during fermentation and also during respiration

Answer 3

T

Question 4

What are the differences between fermentation and respiration

Answer 4

Question 5

T or F : fermentation only yield 2 ATP

Answer 5

T, through glycolysis only

Question 6

What is an anapleurotic pathway?

Answer 6

chemical rxn that form intermidiates of a metabolic pathway. The anapleurotic pathways will replinish the pools of the intermidiate of a metabolic reaction. For example, in the TCA cycle, malate can be replinished by the use of reducing power to convert pyruvate to malate.

Question 7

What are the two biosynthetic roles of the TCA cycle seen in class?

Answer 7

1. oxalactate to make amino acids
2. Malate used in metabolic functions and replinished by anapleurotic pathways

Question 8

In eukaryotes, here are located the enzymes of :

1. TCA
2. Respiration
3. oxidative phosphorylation

Answer 8

ALL in the mitochondria

Question 9

In eukaryotes, where are located the enzymes of the fermentation and glycolysis?

Answer 9

in the cytoplasm

Question 10

What are the pathway that occur in the cytoplasm for both procaryotes and eukaryotes?

Answer 10

Pentose phosphate, glycolysis and fermentation

Question 11

In procaryotes, where is located :

1. respiratory chain
2. glycolysis
3. TCA cycle
4. Fermentation

Answer 11

the respiratory chain is located in the cytoplasmic membrane, while

enzymes of glycolysis, TCA cycle and fermentation are located in the cytoplasm.

Question 12

T or F : eukaryotes produce more energy from the oxidation of one molecule of glucose

Answer 12

False, inverse. the complete oxidation of one molecule of glucose in eucaryotes doesn’t yield as much as energy as it does it procaryotes because the pyruvate and the two NADH produced during glycolysis needs to be actively transported into the mitochondrion

Question 13

T or F : Polar and charged molecules cannot diffuse, must be transported another way

Answer 13

T

Question 14

What are the two modes of transport

Answer 14

Question 15

What dictate the direction of the flow for uncharged molecules that are transported by passive transport?

Answer 15

The gradient

Question 16

What dictate the direction of the flow for charged molecules that are transported by passive transport?

Answer 16

The gradient and the and the charge

Question 17

What are the differences between simple diffusion and transport?

Answer 17

1. Saturation possible with the transport proteins while not possible with the simple diffusion
2. Transport system are specific

Question 18

State the difference between the mutlicellular and unicellular organisms in the way nutritens are taken by the cells.

Answer 18

• In multicellular organisms, cells usually acquire nutrients by means of diffusion or facilitated diffusion (from blood / plasma).
• In unicellular organisms, including bacteria,archaea and eukaryotes, nutrients are usually acquired by active transport.

Question 19

what are the two types of facilitated diffusion?

Answer 19

Carrier mediated and channel mediated.

Question 20

Which one is more specific, carrier mediated or channel mediated?

Answer 20

Carrier mediated

Question 21

What are the three types of active transport?

Answer 21

1. Simple transport
2. Group translocation
3. ABC transporter

Question 22

What are the three type of simple transport?

Answer 22

uniporter, symporter and antiporter

Question 23

Complete : the simple transport is powered by the ____ and requires ___

Answer 23

PMF
energy

Question 24

How can we keep glucose inside the cells if it diffuse easily?

Answer 24

Give it a charge during the group translocation.

Question 25

What is the name of the system that is responsible for the first step fo the glycolytic pathway in procaryotes?

Answer 25

phosphoenolpyruvate-dependent sugar phosphotransferase system

Question 26

What is the phosphoenolpyruvate‐dependent sugar phosphotransferase system.

Answer 26

System with 5 enzymes that passes a phosphate group to the Enzyme 11C (transporter) that will add a posphate to glucose

Question 27

What are the three components of the ABC transporter?

Answer 27

1) A substrate‐specific binding protein that has very high affinity for a specific substrate (or a class of substrates).
2) A membrane‐spanning protein, the active transport carrier.
3) An ATP‐hydrolyzing protein that provides the energy

Question 28

What are the differences between the binding protein of the ABC transporter for the gram positive and the gram negative?

Answer 28

Gram + : protein achanchored in the cytoplasmic memb
Gram - : protein free in the periplasm

Question 29

State the driving force in those cases :
1. Cation (+), ex: potassium that goes through a Cation uniporter net charge : -

2. Anion (‐), ex: sulfate that goes through a proton‐Anion symporter net charge : 0
3. X (Neutral), ex: lactose that goes through a Proton‐X symporter net charge of: +

Answer 29

1. • ΔΨ
2. −zΔpH
3. Δp = ΔΨ − zΔpH

Question 30

State the driving force in each cases

Answer 30

Question 31

What are the differences in the P-type atpase in eukaryotes and the F-type atpase in procaryotes?

Answer 31

Eukaryotes: P‐type ATPase = 1H+ / ATP hydrolyzed

Prokaryotes / Mitochondria: F‐type ATPase = 3H+ / ATP hydrolyzed

Question 32

What are the three type of endocytosis?

Answer 32

Question 33

What component of the cytoskelet is important for the endocytosis

Answer 33

actin filaments