Metabolism

Question 1

Oxidoreductase

Answer 1

oxidation reduction

includes: oxidases, reductases, dehydrogenases

Question 2

transferases

Answer 2

functional group is transferred

includes: kinase, phosphorylase

Question 3

hydrolase

Answer 3

cleave of one molecule into two molecules using water

ex: phosphatase, protease, lipases, nucleases

Question 4

lyase

Answer 4

break bonds without the removal of water; usually results in a double bond

ex: decarboxylase, synthase, aldolase

Question 5

isomerase

Answer 5

functional group movement within a molecule

ex: mutase

Question 6

ligases

Answer 6

joining two molecules to form one via bond formation and ATP hydrolysis

ex: carboxylase, synthetase

Question 7

condensation

Answer 7

releases water to connect two molecules to form one

Question 8

fatty acid synthesis

Answer 8

occurs in the cytosol

combines malanoyl CoA + acetyl CoA and oxidized NADPH –> NADP+ to create palmitate

creates a long chain of fatty acids stuck together in the cytosol

uses acyl carrier protein

uses ATP –> ADP + Pi

1. condensation
2. reduction (NADPH –> NADP+)
3. dehydration (remove H2O)
4. reduction (NADPH –> NADP+)

Question 9

anabolic reactions

Answer 9

build complex molecules from less complex things

requires energy, reducing power, and sufficient precursor molecules to build new macromolecules

Question 10

pentose phosphate pathway

Answer 10

oxidative phase: produces NADPH
non-oxidative phase: uses ribulose 5 phosphate to go through a series of steps which can create DNA/RNA
- also another way to oxidize glucose. Can end up with glyceraldehyde 3 phosphate

Question 11

What is the rate limiting step for the PPP?

Answer 11

glucose-6-phosphate dehydrogenase

activated by NADP+ and inhibited by NADPH and insulin

Question 12

what is different about long fatty acid chains than medium and small chains for beta-oxidation?

Answer 12

small and medium fatty acid changes can diffuse through the inner and outer membrane to enter mitochondria

long fatty acid chain requires to be transported into the mitochondria using carnitine to transfer through tranferase

Question 13

carnitine palmitoyltransferase (CPTI) does what?

Answer 13

converts fatty acyl CoA to fatty acylcarnitine

rate limiting step

Question 14

How does long chain fatty acid move from cytosol to inner membrane space?

Answer 14

acyl synthetase converts fatty acid into fatty acyl CoA which can diffuse through layer

Question 15

what does translocase do?

Answer 15

transfers fatty acylcarnitine from IM space to matrix

Question 16

what does carnitine palmitoyltransferase (CPTII) do?

Answer 16

CPTII converts fatty acylcarnitine back into fatty acyl CoA to begin beta oxidation because is now located in matrix

Question 17

How does acetyl CoA move out of the matrix to the cytosol for fatty acid synthesis?

Answer 17

acetyl CoA + oxaloacetate ==> citrate which can diffuse between the mitochondrial layers and will revert back to acetyl CoA + oxaloacetate once back in cytosol

Question 18

what does pyruvate dehydrogenase complex require to make acetyl CoA

Answer 18

CoA, TPP, lipoic acid, and NAD+

Question 19

insulin

Answer 19

released from beta cells of pancreas islets of Langerhans in response to high blood glucose levels

increases:
glycogen synthesis
lipogenesis
protein synthesis
glycolysis

decreases:
glycogenolysis
gluconeogenesis
lipolysis
ketogenesis

activates pyruvate dehydrogenase complex

Question 20

glucagon

Answer 20

released from alpha cells to increase blood glucose levels

Question 21

acetyl CoA carboxylase

Answer 21

conversion of acetyl CoA –> malonyl CoA with the addition of CO2 using ATP

• required for fatty acid synthesis

Question 22

hormone sensitive lipase

Answer 22

helps triacylglycerides break down into fatty acids and glycerol

activated by glucagon and inhibited by insulin

Question 23

transamination

Answer 23

transfer of amine group

alpha amino acid transfers amine to alpha ketoglutarate to become glutamate. alpha amino acid turns into alpha keto acid

glutamate will donate NH3+ to be combined with CO2 to enter urea cycle, and will revert back to alpha ketoglutarate

Question 24

protein catabolism

Answer 24

breakdown of polypeptide chains and proteins into individual amino acids to produce ATP, glucose, or new proteins

Question 25

glucogenic

Answer 25

amino acids are converted to pyruvate or CAC intermediates --> convert to glucose

Question 26

ketogenic

Answer 26

amino acids are converted directly to acetyl CoA which can enter CAC or become ketone bodies

Question 27

product inhibition

Answer 27

type of negative feedback in which the end product of a reaction pathway decreases its own production by binding to enzyme or regulatory protein needed in an earlier step

Question 28

constitutional isomers

Answer 28

same molecular formula with different bonding types at at least one position D glucose vs D fructose D glucose is an aldose and D fructose is a ketose

Question 29

epimers

Answer 29

differ at only one stereocenter D-glucose and D-mannose only different at one position

Question 30

anomers

Answer 30

differ at the anomeric carbon

Question 31

enantiomers

Answer 31

differ at every single stereocenter awkward turtle where they fit on top of each other but stick out because opposite orientation D-mannose and L-mannose

Question 32

glycosidic bonds

Answer 32

bonds between anomeric carbons of carbohydrates and any other biological molecule must have a free anomeric carbon so cannot be sucrose

Question 33

sucrose

Answer 33

cannot form glycosidic bonds because are linked by anomeric carbons glucose + fructose

Question 34

lactose

Answer 34

disaccharide | glucose + galactose

Question 35

maltose

Answer 35

disaccharide | glucose + glucose

Question 36

monosaccharides

Answer 36

glucose, galactose, fructose, ribose have a free anomeric carbon which can be linked via glycosidic bonds --> reducing ring because donate hydrogens and become oxidized when form bond

Question 37

What is the most common nonreducing sugar?

Answer 37

sucrose | cannot form glycosidic bonds because does not have a free anomeric carbon

Question 38

What pathways can fructose 6 phosphate enter?

Answer 38

glycolysis and become fructose 1,6 biphosphate gluconeogenesis and become glucose 6 phosphate OR combine with glyceraldehyde 3 phosphate and enter PPP to become ribose 5 phosphate

Question 39

glycogen is linked horizontally via

Answer 39

alpha 1-4 subunits

Question 40

glycogen is branched with connections via

Answer 40

alpha 1-6 subunits, about every 10 glucose molecules | glycogen branching enzyme

Question 41

glycogenolysis

Answer 41

breakdown of glycogen occurs when low blood glucose glycogen becomes glucose 1 phosphate + glycogen(n-1) through glycogen phsophorylase

Question 42

glycogen phosphorylase

Answer 42

breaks down glycogen into glucose 1 phosphate + glycogen (n-1) breaks bond between 2 adjacent glucose molecules in a glycogen chain by phosphorolysis (addition of phosphate)

Question 43

ubiquitination

Answer 43

ATP dependent process that adds a target molecules (ubiquitin) to a target protein which will signal the protein to enter the proteosome to be cleaved into small peptides via proteolysis

Question 44

hydroxylated

Answer 44

adding an OH group

Question 45

proteins that are ubiquitously expressed

Answer 45

have consistent concentration levels across all cell/tissue types used as loading controls to show that all lanes in a gel have the same amount of sample loaded into them

Question 46

Cori cycle

Answer 46

process of carrying lactate from the muscle to the liver and moving regenerated glucose from the liver to them muscles it connects gluconeogenesis and glycolysis

Question 47

In a 16 carbon fatty acid, how many ADP and NADP+ molecules will be produced?

Answer 47

7 ADP and 14 NADP+ need to make malonyl CoA from acetyl CoA 7 times and then will need to reduce the bonds using NADPH --> NADP+ 14 times

Question 48

Can a furanose or pyranose form a phosphodiester bond?

Answer 48

Only furanose can form a phosphodiester bond because it needs a free 5' OH group that can grab onto the phosphate pyranose has that 5' O group inbedded into the cyclical structure and would take on an unstable positive charge if it bound to a phosphate

Question 49

nucleotide

Answer 49

contains a nitrogenous base, ribose, and a triphosphate group linked to the 5' carbon of ribose ribose is a 5 carbon sugar (pentose) and must adopt the furanose form to be incorporated into the nucleotide triphosphates

Question 50

How many electrons does NADH hold?

Answer 50

NADH can hold up to 2 electrons so can FADH2, but it can only pass 1 electron at a time. Same with ubiquinol. cytochrome C can only hold and transfer one electron at a time

Question 51

How many electrons is required to turn O2 into water?

Answer 51

4 electrons so 2 NADH molecules are needed to pass their electrons through the ETC

Question 52

What will deaminated alanine become?

Answer 52

deamination means that the NH3 group comes off this will turn alanine into pyruvate

Question 53

Citrate shuttle

Answer 53

pyruvate and citrate can cross over between cytoplasm and mitochondria they also both can convert into oxaloacetate which means that: citrate --> oxaloacetate will remove acetyl CoA into the cytoplasm oxaloacetate --> citrate will hide acetyl CoA within citrate so that it can be transported into the cytosol and can participate in fatty acid synthesis.

Question 54

What happens when triacylglycerol is needed?

Answer 54

It is released from adipocytes when there is low energy and we have run out of glucose 3 fatty acids and 1 glycerol will be released

Question 55

What happens to the fatty acids that are released from a triglyceride?

Answer 55

They will undergo beta oxidation to be broken down into acetyl CoA which will enter the CAC

Question 56

What happens to the glycerol backbone when it is released from triacylglycerol?

Answer 56

It will be converted: glycerol --(glycerol kinase)--> glycerol 3 phosphate --(glycerol phosphate dehydrogenase)--> DHAP --(triose phosphate isomerase)-->glycerol 3 phosphate which can enter glycolysis or gluconeogenesis depending on the need by the body

Question 57

What is required for long chain fatty acids to move into the mitochondria?

Answer 57

the long chain fatty acid must be modified - acyl CoA synthetase adds on a CoA to form acyl CoA but this reaction is thermodynamically unfavorable and requires ATP --> ADP hydrolysis to proceed - acyl CoA migrates to intermembrane space where reacts with carnitine to form acylcarnitine - acylcarnitine translocase will carry acylcarnitine into mitochondrial matrix where it is converted back to acyl CoA and carnitine acyl CoA is then digested by Beta oxidation and carnitine is transported back to the intermembrane space where it will be able to pick up another long chain fatty acid.

Question 58

Citrate shuttle

Answer 58

pyruvate and citrate can cross over between cytoplasm and mitochondria they also both can convert into oxaloacetate which means that: citrate --> oxaloacetate will remove acetyl CoA into the cytoplasm oxaloacetate --> citrate will hide acetyl CoA within citrate so that it can be transported into the cytosol and can participate in fatty acid synthase.