DAT Bio

Question 1

Gibbs FE Formula

Answer 1

delt G = delt H - t delt S

Question 2

cell metabolism

Answer 2

the sum of all chemical reactions in a cell
(metabolism= catabolism + anabolism + energy transfer)

Question 3

Catabolism:

Answer 3

the breakdown of complex molecules into
simpler molecules. Releases energy which can drive
anabolic pathways

Question 4

Anabolism:

Answer 4

the synthesis of complex molecules from
simpler ones, using energy

Question 5

3 Laws of thermodynamics:

Answer 5

1. Energy cannot be created or destroyed – only
   transferred and transformed
2. Entropy of closed systems tends to increase over
   time.
   a. Livings organisms are not closed systems, so
   they can become more ordered (decreased
   entropy) over time by increasing disorder in
   their surroundings
3. Entropy minimizes as a system approaches absolute
   0 Kelvin

Question 6

Substrate:

Answer 6

the molecule that an enzyme acts on

Question 7

Active site:

Answer 7

the location on the enzyme where the
substrate binds. The shape of the active site
determines the enzyme’s substrate specificity (i.e. what
molecules it can interact with)

Question 8

Cofactors:

Answer 8

nonprotein structures that assist enzymes in
their function. Can bind permanently or reversibly.

Question 9

Ribozymes:

Answer 9

RNA molecules with enzymatic function

Question 10

Vmax:

Answer 10

maximum rate of a reaction

Question 11

Vmax increases as

Answer 11

the amount of substrate increases.
- Limited by enzyme saturation (increasing enzyme
concentration also increases Vmax)

Question 12

1/2 vmax

Answer 12

half of the max rate

Question 13

Km (Michaelis Constant):

Answer 13

the concentration of substrate
at 1⁄2 Vmax. Inversely proportional to substrate binding
affinity (how well the enzyme binds to a substrate)

Question 14

Small Km:

Answer 14

high binding affinity; less substrate
needed to saturate the enzyme

Question 15

Large Km:

Answer 15

low binding affinity; more substrate
needed to saturate the enzyme

Question 16

Competitive Inhibition:

Answer 16

inhibitor reversibly binds to
the active site. Can be overcome by increasing
substrate concentration.

Question 17

Non-Competitive Inhibition:

Answer 17

the inhibitor binds to the
enzyme at a location other than the active site. Cannot
be overcome by increasing substrate concentration.
- Vmax decreases, Km is unaffected

Question 18

Allosteric Inhibition:

Answer 18

inhibitor binds to the allosterc site
of enzyme and induces the enzyme’s inactive form.
Allosteric inhibition is a form of non-competitive
inhibition.

Question 19

Cellular Respiration:

Answer 19

combination of aerobic and anaerobic 1
catabolic pathways that cells use to breakdown organic
compounds (e.g. glucose) into ATP

Question 20

Aerobic Cellular Respiration of glucose: consists of 3 steps

Answer 20

1. Glycolysis (in cytosol of cell)
2. Citric Acid/Krebs/Tricarboxylic Acid Cycle (in
   mitochondrial matrix)
3. Oxidative Phosphorylation/Electron Transport Chain
   (across inner mitochondrial membrane)

Question 21

Mitochondria

Answer 21

critical to cellular respiration in eukaryotic
cells as they are the site of aerobic cellular respiration to
synthesize ATP.

Question 22

Overall Reaction of Cellular Respiration:

Answer 22

C6H12O6 (glucose) + O2 ➞ 6CO2 + 6H2O + Energy

Question 23

Glycolysis

Answer 23

Glucose + 2 NAD+ + 2 ADP ➞ 2 Pyruvate + 2 ATP + 2
NADH + 2 H2O

Question 24

Pyruvate decarboxylation:

Answer 24

if oxygen is present, pyruvate is
converted into acetyl CoA in the mitochondrial matrix

Question 25

CAC summarized:

Answer 25

Acetyl CoA from pyruvate decarboxylation merges with oxaloacetate to form citrate ➞ citrate undergoes 7 more steps, forming different intermediates ➞ oxaloacetate is reformed ➞ cycle repeats

Question 26

Electron Transport Chain (ETC):

Answer 26

a series of proteins which pass high energy electrons to each other; embedded in the inner membrane of the mitochondria

Question 27

Final step of ETC:

Answer 27

electrons are transferred to O2. The O2, protons, and electrons combine to form water (H2O)

Question 28

ATP Synthase:

Answer 28

makes ATP from ADP via oxidative phosphorylation, powered by the proton-motive force. Embedded in inner mitochondrial membrane.

Question 29

Proton-Motive force:

Answer 29

gradient of protons (high [H+] in intermembrane space, low [H+] in mitochondrial matrix) forming electrochemical gradient

Question 30

Chemiosmosis:

Answer 30

movement of ions down a concentration gradient across a semipermeable membrane

Question 31

Protons flow down their gradient (from the intermembrane space into the mitochondrial matrix) through

Answer 31

ATP synthase

Question 32

Anaerobic respiration:

Answer 32

cellular respiration (glycolysis ➞ CAC ➞ ETC) that occurs with molecules other than O2 as the final e- acceptor (e.g. SO42-, NO3- , S).

Question 33

Fermentation:

Answer 33

anaerobic recycling of NADH into NAD+ from pyruvate. Occurs in the cytoplasm of the cell and does not generate any ATP (only regenerates NAD+)

Question 34

2 types of fermentation

Answer 34

alcohol and lactic acid

Question 35

Glycogenesis:

Answer 35

body stores extra glucose as glycogen by linking glucose molecules together.

Question 36

Glycogenolysis:

Answer 36

breakdown of stored glycogen into glucose for energy. Occurs when glucose levels are low.

Question 37

Gluconeogenesis:

Answer 37

synthesis of glucose from non-carbohydrate molecules (proteins and lipids). Occurs in the liver and the kidney when glucose and glycogen levels are low.

Question 38

Glycolysis:\

Answer 38

breakdown of glucose to make pyruvate and produce ATP.

Question 39

Insulin:

Answer 39

endocrine hormone released when blood glucose is high.

Question 40

Glucagon:

Answer 40

released when blood glucose is low.

Question 41

lipolysis,

Answer 41

triglycerides are broken down into glycerol + 3 fatty acid chains

Question 42

Oxidative deamination:

Answer 42

removal of amino group from amino acids in order to make other metabolic intermediates. Mostly occurs in the liver.