Exam 2 Short Answer Definitions

Question 1

Cytosol (animals, yeast cells)

Answer 1

NADPH production, isopremoid and sterol synthesis, Fatty acid synthesis

Question 2

ER (both)

Answer 2

Phospholipid and sterol synthsis, FA elongation, FA desaturation

Question 3

Mitochondria (animals, yeast cells)

Answer 3

FA oxidation, Acetyl-CoA production, Ketone Body synthesis, FA elongation

Question 4

Mitochondria (plants)

Answer 4

No FA oxidation

Question 5

Peroxisomes (plants)

Answer 5

FA oxidation (--> H2O2)
Catalase, Peroxidase (H2O2--> H2O)

Question 6

Chloroplasts (plants)

Answer 6

NADPH, ATP production, [NADPH]/[NADP+] high, FA Synthesis

Question 7

Cytosol

Answer 7

Place where FA synthesis occurs in many organims

Question 8

Chloroplasts

Answer 8

Place where FA synthesis occurs in plants

Question 9

Saturated acyl group

Answer 9

Product of FA synthesis which becomes the substrate for condensation with an activated malonyl group

Question 10

Palmitic Acid

Answer 10

16:0

The product that leaves the FA cycle once the chain length reaches 16 carbons

Question 11

Fatty Acid Synthase

Answer 11

Multienzyme complex that carries out all of the reactions of fatty acid synthesis
Contains 7 activites

Question 12

NADPH

Answer 12

Used to reduce the double bonds that are inserted in the growing acyl chain when malonyl-CoA condenses with Acetyl-CoA

Question 13

Palmitic Acid

Answer 13

Serves as the precursor for the biosynthesis of long-chain saturated fatty acids in animal cells

Question 14

Palmitoyl-CoA

Answer 14

Is extended by 2 carbons to form Stearoyl-CoA

Question 15

Stearoyl-CoA

Answer 15

Formed when Palmitoyl-CoA is extended by 2 carbons

Question 16

Fatty Acyl-CoA Desaturases

Answer 16

Action that forms unsaturated fatty acid

These desaturases are types of mixed function oxidases

Question 17

Mixed Function Oxidase

Answer 17

The enzyme oxidizes 2 different substrates simultaneously

Question 18

Triacylglycerols and Phospholipids

Answer 18

Share the same initial pathway that forms Glycerol-3-Phosphate

Question 19

Acyl transferase

Answer 19

Adds 2 acyl esters to the glycerol phosphate molecule

Question 20

Acyl-CoA Synthetase

Answer 20

Converts fatty acids to their active CoA thioester

Question 21

Phosphatidic acid

Answer 21

1,2-diacylglycerol-3-phosphate

Serves as the common precursor for both TAG and Phospholipid synthesis and is thus a branch point

Question 22

Cytidine Diphosphate-diacylglycerol

Answer 22

Formed from phosphatidic acid by the enzyme CTP: Phosphatidate cytidylyl transferase

Question 23

CDP-DAG

Answer 23

Contains a high energy bond between the phosphates

Can act as a donor of DAD or Phosphatidyl radical

Question 24

Head group exchange

Answer 24

Process by which animals produce phosphatidyl serine

Question 25

SAM

Answer 25

S-adenosyl methionine

Question 26

SAHC

Answer 26

S-adenosyl-hamocysteine

Question 27

Fusogenic Membrane

Answer 27

Primarily composed of PE and PS ideally in 3:1 ratio

Question 28

Membrane Fusion

Answer 28

Primary means to change membrane composition and is a major mechanism involved in endocytosis and exocytosis

Question 29

PE

Answer 29

Phosphotidylethanolamine: least hydrated phospholipid head group and doesn't attract to water easily

Question 30

Hexagonal II

Answer 30

Inverted membrane head groups facing fatty acid (outwards) | Formed from PE

Question 31

Intermembrane van der Waal attractions

Answer 31

Enhanced by Ca+2 binding to PS

Question 32

When calcium binds to PS

Answer 32

It reduces the net surface charge density and reduces surface hydration repulsion

Question 33

Peripheral Membrane proteins

Answer 33

Can be removed from the membrane by using buffers containing salt and/or buffers at extreme physiological pHs

Question 34

Integral Membrane Proteins

Answer 34

Can only be removed by buffers with detergent | Hydrophobic

Question 35

Hydropathy Plots

Answer 35

Attempt to predict membrane spanning alpha-helical regions from amino acid sequences

Question 36

Transmembrane Spanning Regions

Answer 36

About 20 amino acids long and consist primarily of hydrophobic amino acids

Question 37

Kyle and Doolittle Scale

Answer 37

Uses hydrophobicity of amino acids as measured by the hydration potential. The frequency residues are found in globular water soluble protein and amino acids relatively polar

Question 38

Really hydrophobic amino acids

Answer 38

Isoleucine, Valine, Leucine