Into to metabolism flashcards

Question 1

Metabolism

Answer 1

Sum of all chemical reactions that occur in a cell, tissue, or the body. Process is heavily regulated and every reaction is catalyzed by enzymes.

Question 2

Catabolic

Answer 2

Break down fuel molecules

Question 3

Anabolic

Answer 3

Build molecules to produce fuel. Glucose, fatty acids, and some amino acids can be produced.

Question 4

Exergonic reaction

Answer 4

delta G < 0 and proceeds towards equilibrium (spontaneous). Make ATP, NADH, and NADPH

Question 5

Endergonic reaction

Answer 5

delta G > 0 and energy is needed for it to occur (not spontaneous). Use ATP and NADPH

Question 6

Equation for delta G

Answer 6

delta G = delta H - T (delta S)

Question 7

NADH

Answer 7

Intermediate which can be oxidized in terminal oxidation to produce ATP

Question 8

5 reasons to use ATP

Answer 8

1. Stores energy in high-energy chemical bonds 2. Links energy producing and energy using systems (universal free energy currency) 3. Chemical energy in ATP can be turned into other energies (chemical, mechanical, heat) 4. Acts as a second substrate (like in kinases/phosphatases) 5. May act as an allosteric effector (change conformation of protein to turn pathway on or off)

Question 9

Energy-rich molecules

Answer 9

ATP, CTP, GTP, NADPH, NADH, UTP, Acetyl CoA and succinyl CoA (TCA cycle) , 1,3-biphosphoglycerate and phosphoenolpyruvate (glycolysis)

Question 10

Anaplerotic reactions

Answer 10

Amino acids can join up in the pathway anywhere and fill in missing intermediates

Question 11

What is the only energy-generating path in the cytosol?

Answer 11

Glycolysis utilizing glucose which is an anaerobic process

Question 12

How do brain cells get fatty acid nutrients?

Answer 12

Ketone bodies produced in the liver which can pass the blood-brain barrier

Question 13

How does the presence of mitochondria and oxygen affect types of fuel molecules which can be used in cells?

Answer 13

All cells use glucose through glycolysis to make energy (oxygen and mitochondria are not required). Need both mitochondria and oxygen to use glucose, fatty acids, and amino acids in the citric acid cycle.

Question 14

Stepwise degredation of nutrients (3)

Answer 14

1. Take up and digest nutrient macromolecules 2. Building blocks further degraded 3. Energy generated to yield ATP

Question 15

4 major energy-generating reactions in the mitochondria

Answer 15

1. Pyruvate dehydrogenase complex (PDH) 2. Fatty acid beta-oxidation 3. Krebs cycle (TCA) 4. Terminal oxidation (Electron transport + Oxidative phosphorylation) takes place in the mitochondrial inner membrane. All other reactions are in the mitosol (mitochondrial matrix)

Question 16

Pyruvate dehydrogenase complex (PDH)

Answer 16

Mitochondrial complex of 3 enzymes which convert pyruvate into acetyl-CoA using pyruvate decarboxylation which is IRREVERSIBLE

Question 17

Outer membrane of mitochondria

Answer 17

Simple membrane with a few enzymatic/transport functions. Permeable for most molecules.

Question 18

Inner membrane of mitochondria

Answer 18

Complex with 80% protein content. Very selective permeability. Contains most of electron transport and oxidative phosphorylation enzymes, various dehydrogenases, and transport systems.

Question 19

Mitochondiral DNA

Answer 19

Circular because of bacterial origin. Many disorders are related to the circular DNA. Passed down through mother.

Question 20

2 ways for molecules to pass inner mitochondrial membrane

Answer 20

1. Transporters 2. Shuttles

Question 21

Transporters

Answer 21

Exchange ATP for ADP and Pi to move TCA intermediates in and out of mitochondrial membrane

Question 22

Shuttles

Answer 22

Transport protons and electrons from NADH derived from glycolysis across inner mitochondrial membrane where they are oxidized

Question 23

Atractyloside

Answer 23

Plant toxin which inhibits the adenine nucleotide transporter (exchanges ADP for ATP) on the inner mitochondrial membrane

Question 24

Mersalyl

Answer 24

Mercury compound which inhibits the phosphate transporter on the inner mitochondrial membrane

Question 25

Malate-aspartate and Alpha-glycerol phosphate shuttles

Answer 25

Irreversible transfer reducing of equivalents (protons and electrons) from cytosol to the mitosol where they are oxidized. Also reconstruct NAD+ to get back to cytosol so there is enough for glycolysis and other NAD+ requiring reactions.