HCC DR. Harold Kay test 8,9,11, Njemanze Test 3 chapters 8, 9 , 10, 11

in chargaffs antiparallel rule DNA polymearse 1 removes the RNA primers

removes the RNA primers and replaces them with DNA

chargaffs rule antiparallel one helix runs from 5 phosphate to OH and the other run from

3 to 5 direction ( 5means carbon #5 of deoxyribose. 3 means carbon #3)

metabolism

all the chemical and physical processes of an organism.

catabolic pathway

process that breaks down macromolecules to produce simpler units, with the release of energy.

since energy is released it is an exergonic reaction.

anabolic pathway

process that builds up complicated molecules from simpler units, with the consumption of energy. since energy is consumed it is an endergenic reaction.

enzymes

catalytic agents : biological catalyst

catalyst

chemicals capable of increasing rate of reaction, without becoming consumed at the end of the reaction.

when naming inorganic enzymes, what do they typically end with?

usually inorganic enzymes end in ASE

what are enzymes composed of ?

protein molecules

what are simple enzymes?

enzymes that consist of protein alone

conjugated enzymes (holoenzymes)

consist of both protein and nonprotein molecules

apoenzyme

is the protein portion

cofactor

is the nonprotein portion

what is a coenzyme?

an organic cofactor

cofactors may be ____ or ____ molecules

organic, inorganic

what is metallic?

inorganic cofactor

how do enzymes increase the rate (speed) of reaction

by decreasing the activation energy

where does the substrate (metabolite) attaches to a specific site on the enzyme called

the active site

what forms a enzyme-substrate complex

when a substrate (metabolite) attaches to a specific site on the enzyme called the active site

what changes does a substance molecule go through

breakdown, combination

why are enzymes specific for their substrates

due to the 3 dimensional shape of the active site, which fits the substrate in a lock and key

enzyme characteristics

1. most enzymes are composed of proteins. (may require a cofactor)

2. speed up the rate of chemical reactions

3. are organic catalyst

4. lower activation energy (ea)

5. have a restrictive region called an active site

6. reacts with a molecule called a substrate

7. usually larger than the substrate

8. are not consumed at the end of reaction

9. are affected by temperature and ph

10. can be regulated by feedback and genetic mechanism

each demonstrate specificity, it acts only upon one particular substrate

most enzymes are composed of

proteins. . (may require a cofactor)

actor)

enzymes speed up the rate of

chemical reactions

what kind of catalyst are enzymes

organic catalyst

enzymes lower

activation energy

enzymes have a restrictive region called

active site

enzymes reacts with a molecule called a

substrate

enzymes are usually larger than

substrate

enzymes are not consumed at the end of

reaction

Enzymes are affected by

temperature and ph

enzymes can be regulated by

feedback and genetic mechanism

each enzyme demonstrate specificity by

acting only upon one particular substrate

exoenzymes

transported extracellularly, to break down macromolecules or harmful chemicals . ex. cellulose, amylase, and penicillinase

endoenzymes

produced and retained inside the cell and function there. ex. most enzymes of the metabolic pathways

constitutive enzymes

always present, always produced in equal amounts or at equal rates, regardless of amount of substrate. ex. enzymes involved in glucose metabolism

ENDOENYZMES most enzymes of the

metabolic pathways

regulated enzymess

not constantly present, production is turned on (induced) or turned off (repressed) in response to changes in concentration of the substrate

constitutive enzymes are enzymes involved in what kind of metabolism

glucose metabolism

what are enzymes affected by?

temperature and ph

what does being above or below a ph or 6-8 do to an enzyme

causes denuration of the enzyme, alteration of active site and loss of catalytic ability

substrate concentration

optimum concentration of substrate is the maximum rate at which the enzyme can perform catalytic activities

what does maximum or ph concentration do ?

causes the enzyme to be saturated, which means that the active site is always occupied by the substrate or products

what does an increase in saturation do ?

does not effect the reaction rate any further, since all the active sites are already occupied.

lack of substrates causes the enzyme to become...

an inactive inhibitor

inhibitors

have a direct control on the behavior of enzymes,

competitive inhibitors

substance that resembles normal substrate competes with the substrate for the enzyme active site.

noncompetitive inhibitors

do not compete with the normal substrate over the enzymes active site, also called allosteric regulation

allosteric regulation

similar to noncompetitive inhibitors

feedback repression

a part of noncompetitive

inhibitors that inhibits at the genetic level by controlling synthesis of key enzymes

feedback inhibition

a part of noncompetitive

inhibitors it is a concentration of product at the end of a pathway blocks the action of a key enzyme

enzyme induction

a part of noncompetitive

inhibitors .the enzymes are made only when suitable substrates are present

can inhibiton be genetically controlled?

yes

oxidation reduction reaction

chemical reactions which involve a partial or complete transfer of electrons from one reactant to another. this is called redoc rx for short

oxidation

patrial or complete loss of electrons

reduction

partial or complete gain of electrons

redox reactions what does this action require?

a doner and an acceptor

so when one reactant is oxidized the other is ....

reduced

cellular respiration

organic compound + oxygen --> carbon dioxide + water + energy

cellular respiration involves how many steps?

3

gylcolysis

krebs cycle

electron transport chain

gylcolysis/ substrate level phosphorylation

this is ATP production by direct enzymatic transfer of phosphate from an intermediate substrate in catabolism to ADP. This is a catabolic pathway

how many steps does gylcolysis require?

10 steps

first five steps of glycolysis

called the energy investment phase ( bc ATP is used)

last five steps of glycolysis

called the energy yeilding stage

is oxygen used in glycolysis?

no, therefore considered anarobic

one molecule of glucose produces what in glycolysis?

2-3C molecules called pyruvate

in glycolysis how many atp to start reaction

investment of 2 atp

in glycolsis how many total atp are produced

4 atp

in glycolsis how many net atp are produced

2 ATP

what else is produced in glycolysis

2 nadh and 2 hydrogen ions

what does glycolysis take place?

in the cytosol of the cytoplasm, of ALL cell types ( pro and eukar)

during the connecting step how many pyruvates enter the mitochondrial matrix?

2 pyruvates

during the connecting step what do the two pyruvates convert to

2 acetyl coenzyme A, no atp is produced

no atp is produced but what is?

2 co2 are produced, also 2 nahd and 2 hydrogen ions

where does the production of 2 co2, 2 nadh, and 2 hydrogen ions take place during glycolysis?

mitochondrial matrix

krebs cycle/ TCA/ citric acid cucle/ tricarboxylic acid cycle

this is a catbolic pathway

how does krebs cycle complete glucose oxidation?

by breaking down pyruvate derivitive (acetyl coA) into carbon dioxide

how many times does the krebs cycle go around for each glucose molecule t produce acetyl co a

once

for each glucose molecule, how many times does the krebs cycle go around

twice

during krebs cycle what does each step require?

a specific enzyme

how many total atp are produced in kreb cycle

2 atp, 1 from from each cycle is produced

oxygen used or not in krebs cycle?

no

how many co2 are produced in kreb cycle

4 co2 total, 2 from each cycle is produced

how many nadh are produced in kreb cycle

6 nadh total , 3 from each cycle

how many fadh2 are produced in kreb cycle

2 fadh, 1 from each cycle

for prokaryotes the kreb cycle take place in cells

cytoplasm

in etc oxidative phosphorylation

this is atp production that is coupled to the exergonic transfer of electrons from food to oxygen

the ETC is made up of what? and imbedded where?

electron carrier molecules, inner mitochondrial membrane

in etc most of the carrier molecules are proteins and are tightly bound to a prosthetic groups (nonrotein factors) except for

ubiquinone

in etc the inner mitochondial membrane has a chain of...

electron transport proteins

in etc what is the final electron acceptor?

oxygen

what does oxygen combine with to form what?

2 hydrogen to form water

how does hydrogen move from intermembrane space back to matrix?

through a special protein complex located in the inner mitochondrial membrane called an ATP synthase

what does this flow of hydrogen ion activate?

this enzyme and 6H20 and 34 atp

chemiosmotic synthesis produced how much atp?

90 percent

Does ETC use oxygen?

Yes

where does ETC take place?

cell membrane (prokaryotes)

inner mitochondrial membrane (eukaryotes)

genetics

the study of inheritance or heredity ( similarities to parents) and variablity ( differences from parents)

genome

the sum total of genetic material

usually in the form of a chromosome

genome