mod 1 into to metabolism

Question 1

What is metabolism?

Answer 1

• The sum of all of the chemical reactions occurring in the cell.
• The overall processes by which living things acquire and utilize free energy in the cell
• requires tightly coordinated cellular activity

Question 2

What do living organisms need for metabolism?

Answer 2

A continuous influx of energy to battle entropy. (disorder)

Question 3

What are enzymes in the context of metabolism?

Answer 3

The basic units of metabolism.

Question 4

What are metabolites?

Answer 4

The substrates of enzymes.

Question 5

Define a metabolic pathway.

Answer 5

• A series of connected enzymatic reactions that produces a specific product.
• Consists of sequential steps

Question 6

DRAW the simple glycolysis pathway

Answer 6

Question 7

DRAW elaborate glycolysis pathway with structures

Question 8

DRAW how catabolism and anabolism are related

Answer 8

Question 9

List the four functions of metabolism.

Answer 9

• Obtain free energy for the cell.
• Degrade macromolecules as required for biological function.
• Convert nutrients into macromolecules.
• Assemble macromolecules into cellular structures.

Question 10

What are the two main categories of metabolism?

Answer 10

Catabolism and anabolism.

Question 11

What does catabolism involve?

Answer 11

Degradative pathways/enzymes, usually producing free energy and oxidative.

Question 12

What does anabolism involve?

Answer 12

Biosynthetic pathways, usually consuming free energy and reductive.

Question 13

How is ATP formed?

Answer 13

• via photosynthesis in phototropic cells
• catabolism in heterotrophic cells

Question 14

What does ATP hydrolysis power and how?

Answer 14

Energy requiring cellular activities like biosynthesis, osmotic work, and cell motility/muscle contraction by breaking ATP into ADP and Pi

Question 15

DRAW the ATP cycle

Answer 15

Question 16

Why is ATP considered a ‘high energy’ compound?

Answer 16

Due to hydrolysis which leads to:
- increased resonance stabilization
- decreased electrostatic interaction (charges are usually shielded by Mg2+
- increased energy of solvation (more disordered system)

Question 17

DRAW the complete structure of ATP with all parts labeled

Answer 17

Question 18

What is the Standard Free Energy of phosphate ester hydrolysis of ATP —> ADP + Pi?

Answer 18

-30.5

Question 19

What is the Standard Free Energy of phosphate ester hydrolysis of ATP —> AMP + PPi?

Answer 19

-32.2

Question 20

What is the Standard Free Energy of phosphate ester hydrolysis of ADP —> AMP + Pi?

Answer 20

-35.7

Question 21

What is the Standard Free Energy of phosphate ester hydrolysis of PPi —-> 2 Pi ?

Answer 21

-33.5

Question 22

What are the “high” energy compounds, why are they called this, and what are their Standard Free Energy changes?

Answer 22

They are called this because they can drive ATP synthesis (bc they have more energy than it takes to make ATP)
- Phosphoenolpyruvate (PEP) : - 61.9 kJ/mol
- 1,3 - Bisphosphoglycerate : - 49.4 kJ/mol
- Acetyl phosphate : - 43.1 kJ/mol
- Phosphocreatine : - 43.1kJ/mol

Question 23

What are the “low” energy compounds, why are they called this, and what are their Standard Free Energy changes?

Answer 23

They are called this because they CANNOT drive ATP synthesis (bc they have less energy than it takes to make ATP they fuel…)
- Glucose - 1 - phosphate : - 20.9 kJ/mol
- Fructose - 6 - phosphate: - 15.9 kJ/mol
- Glucose - 6 - phosphate : - 13.8 kJ/mol
- Glycerol - 3 - phosphate : - 9.2 kJ/mol
- AMP —-> adenosine + Pi : -9.2 kJ/mol

Question 24

DRAW the three positions on ATP that undergo Nucleophilic Attack and the mechanism for this

Answer 24

Question 25

What are the three principal nutrients and end products of catabolism?

Answer 25

Nutrients: carbs, fats, and proteins End Products: water, carbon dioxide, and ammonia

Question 26

What are the three principal nutrients and end products of anabolism?

Answer 26

Nutrients: amino acids, sugars, fatty acids, and nitrogenous bases End Products: proteins, polysaccharides, lipids, nucleic acids

Question 27

What is the role of NADH in metabolism?

Answer 27

- used in fuel metabolism - the most common e- carrier and ALWAYS transfers 2 e- at a time

Question 28

What is the role of NADPH in metabolism?

Answer 28

- biosynthesis relies on its reducing equivalents - can be viewed as the carrier of e- from catabolic rxns to anabolic rxns

Question 29

What is the difference between the STRUCTURES of NADH and NADPH

Answer 29

The OH on the 2' carbon is switched for a phosphate group

Question 30

DRAW NADH and NADPH

Answer 30

Question 31

True or False: Catabolism is oxidative while anabolism is reductive.

Answer 31

True.

Question 32

DRAW how NAD+ collects electrons released in catabolism

Answer 32

Question 33

DRAW reduction/oxidation of NAD+ and NADH

Answer 33

Question 34

What are the two ways to manage catabolism and anabolism?

Answer 34

1. Cell maintains tight and separate regulation of catabolism and anabolism so metabolic needs can be met (unique enzymes and pathways) 2. Metabolic pathways are localized within different cellular compartment (COMPARTMENTALIZATION)

Question 35

DRAW how the pathways of catabolism converge to a few end products

Answer 35

Question 36

Compare anabolic and catabolic pathways

Answer 36

- these pathways may involve the same products but are not the same - some steps are common to both (reversible enzymes) - Other steps are different (unique enzymes) to ensure each pathway is spontaneous/thermodynamically favorable - this also allows regulatory mechanisms to turn one pathway ON and the other OFF

Question 37

Define nutrition:

Answer 37

the intake and utilization of food

Question 38

What is the impact of nutrition on metabolism?

Answer 38

Nutrition impacts health, development, and performance by dictating the source of energy that powers your body and the metabolic energy use. - how your body biosynthesizes biomolecules and repairs body tissues is dictated by metabolic energy

Question 39

Define vitamins

Answer 39

organic molecules acquired through diet that assist metabolic reactions

Question 40

Water soluble vitamins :

Answer 40

are almost always converted into coenzymes

Question 41

Fat-soluble vitamins

Answer 41

A, D, E, and K are stored for longer periods of time

Question 42

How are metabolic pathways controlled?

Answer 42

* Thermodynamics * Compartmentalization * Metabolic flux (regulation of key enzymes) * Allosteric control (+ and - regulators, aka allosteric effectors) * Covalent modification (addition of a chemical group that enhances or diminishes enzyme function) * Substrate cycles (control of flux through a pathway by enhancing rates while diminishing those rates in opposition) * Genetic control (control of levels of enzyme biosynthesis)

Question 43

Metabolic pathways must collectively operate as a process of :

Answer 43

supply and demand

Question 44

What is the primary molecule used to power endergonic processes?

Answer 44

ATP; because they are unfavorable or non spontaneous ## Footnote ATP is adenosine triphosphate, which provides energy for various cellular processes.

Question 45

What type of compounds are particularly important in the biosynthesis of ATP?

Answer 45

High energy phosphate compounds because they are coupled to its biosynthesis ## Footnote These compounds have high phosphoryl group transfer potentials.

Question 46

What are the two phases of Glycolysis?

Answer 46

1. Consumes 2 ATP (investment) 2. Produces 4 ATP (payback)

Question 47

PEP is considered a high energy intermediate because it is a potent __________ agent.

Answer 47

phosphorylating ## Footnote The hydrolysis of PEP releases a significant amount of energy.

Question 48

DRAW 1,3 Bisphosphoglycerate2- + h2o ------> 3 Phosphoglycerate3- + 2 Pi2- + H+

Answer 48

Question 49

DRAW PEP3- + h2o -----> pyruvate- + Pi2-

Answer 49

Question 50

DRAW PEP -----> pyruvate and PEP-enol -----> PEP-keto tautomerization

Answer 50

Question 51

What are the two important aspects of biochemistry highlighted?

Answer 51

1. Structure dictates function 2. It's always about energetics

Question 52

What is the outcome of glycolysis in terms of glucose and ATP?

Answer 52

2 Pyruvate and 2 ATP ## Footnote Glycolysis converts glucose into pyruvate while producing ATP.