The energy for chemical reactions is stored in _____________.

ATP

_______ are proteins produced by living cells.

Enzymes

Enzymes function is to _____________________________________.

catalyze cheical reactionsby loering the activation energy

Enzymes are generally __________proteins with characterstic ____________ shape.

globular
3-D shape

Enzymes are efficient and can operate at relatively ________ temperatures and are subject to various cellular controls.

low

Enzyme names usually end in _________.

-ase

The 6 classes of enzymes are defined on the basis of the types of ________ they _____________.

reactions
catalyze

Most enzymes are _____________ consisting of a _________ and a _________.

protein portion- (apoenzyme)
non-protein porttion- (co-factor)

The cofactor can be a __________ (iron, cobalt, copper, magnesium, manganese, zinc and calcium) or a complex organic molecule known as ________________ (NAD+, NADP+, FMN, FAD, or coenzyme A).

metal ion
a coenzyme

True or false. When an enzyme and substrate combine the substrate is transformed and the enzyme is recovered.

true

Enzymes are characterized by ________________ which is characterized by their active sites.

specificity

At ____________ temperatures enzymes undergo ____________ and lose their catalytic properties.

high
denaturation

At __________ temperatures enzymes _________ rate _______________.

low
reaction rate
decreases

The pHat which enzymatic activity is maximal is known as the __________ pH.

optimum

Enzymatic activity increases as substrate concentration ___________ until the enzymes are _______________.

increases
saturated

________ inhibitors compete with normal substrate for the ________ site of the enzyme.

Competitive
active

_________ inhibitors act on other parts of the apoenzyme or on the cofactor and decrease the enzyme's ability to combine with normal substrate.

Non-competiitive

__________ ________ occurs when the end product of a metabolic pathway inhibits an enzyme's activity near the start of the pathway.

Feedback inhibition

________ are enzymatic RNA molecules that cut and splice RNA in eukaryotic cells.

Ribozymes

_______ it the removal of one or more electrons from a substrate. Protons (H+) are removed with the electrons.

Oxidation

Reduction of a substrate refers to its ______ of one or more ______________.

gain
electrons

True or false. Each time a substance is oxidized another is simultaneously reduced.

True

NAD+ is the reduced or oxidized form

oxidized

NADH is the _______form.

reduced

True or false. Glucose is a reduced molecule; energy is released during a cell's oxidation of glucose.

true

Energy released during certain metabolic reactions can be trapped to form _____ from ___________ and (P)-phosphate.

ATP
ADP

Adding a (P) to a molecule is called _______________.

Phosphorylation

During substrate-level phosphorylation a ______________ (P) from an intermediate in catabolism is added to ADP.

high energy

True or False. During oxidative phosphorylation energy is released as electrons are passed to a series of of electron acceptors (an electron transport chain) and finally to O2 or another inorganic compound,

true

Photophosphorylation only happens in ___________ organisms.

photosynthetic organisms

Catabolic reactions:

1.breakdown reactions
2. release energy (exergenic)
3. typically occur via hydrolysis

Anabolic reactions:

Synthesis reactions-put together -build
require the input of energy (endergonic)
typically occur via dehydration synthesis

dehydration synthesis (left to right)

a chemical reaction in which a molecule of water is released in the reaction of the monosaccharides glucose and fructose combine to form a molecule of the disaccharide sucrose.

Hydrolysis (right to left)

in hydrolysis the sucrose molecule breaks down into the smaller molecules glucose and fructose. For the hydrolysis reaction to proceed, water must be added to the sucrose.

What is the most usable form of energy?

ATP

Catabolic ______ and _______ _________.

breakdown
and make ATP

Anabolic ________ and ______ _______.

build and use ATP

There are different types of energy

heat
light-plants
chemical energy

ATP is _____________ energy.

chemical

True or false. Heat is a useless energy it can't be reused.

true

Organic molecules contain energy stored in their bonds. More specifically energy is associated with _______ that form those bonds.

electrons

Most of a cell's energy is produced from the __________ of ________________.

oxidation of carbohydrates

What is the most commonly used carbohydrate?

glucose

The two major types of glucose catabolism are __________in which glucose is completely broken down and _________ is when it is partially broken down,

respiration
fermentation

What is the most common pathway for the oxidation of glucose?

glycolysis

What is the end product of glycolysis?

pyruvic acid

Two ATP and two NADH are produced rom one ________ ________.

glucose molecule

Cells extract energy and store it in ?

ATP

Oxidation reactions involves the oxidation of a molecule. A molecule loses energy-containing electrons. Reduction reactions involves the reduction of a molecule. A molecule gains energy containing electrons. What is a good way to remember this ?

LEO goes GER
Loss of electrons is oxidation; gain of electrons is reduction
or
OIL RIG
oxidation is loss and Reduction is gain

Adenosine triphosphate (ATP) does what?

1. stores chemical energy released by catabolic reactions
2. provides energy for anabolic reactions

What is ATPs structure?

Adenosine unit (ribose and adenine) + 3 phosphate groups (3 like charges forced together =high energy bonds)

What are the three mechanisms of ATP?

1. substrate level phosphorylation - transfer of a high energy phosphate from a phosphorylated compound to ADP (sharing phosphate with ADP)
2. Oxidative phosphorylation- cellular respiration
-ETC creates proton motive force
-H+ channeled through ATP synthase along the concentration gradient
-energy from proton motive force used to phosphorylate ADP
3. Photophosphorylation-Photosynthetic organisms
-occurs only in photosynthetic organisms
-process similar to phosphorylation

During respiration _______ molecules are ________.

organic molecules
oxidized

During cellular respiration energy is generated from the ________________.

Electron transport chain (ETC)

In aerobic respiration what is the final electron acceptor?

O2 (oxygen)

In anaerobic respiration what is the final electron acceptor?

any other inorganic molecule other than O2

Decarboxylation of pyruvic acid produces one CO2 and one ________________ group.

acetyl

True or false. Pyruvic acid cannot enter the Krebs's cycle.

true

Collisions depend on?

molecular speed
molecular energy (only some will have enough)
molecular chemical configurations

Rate of reaction increases when ______________.

Amount of heat is increased
-molecular movement increases
-frequency of collision increases
-number of molecules that are at or above the activation energy level increases
Other ways to increase reaction rate:
-increase the pressure
-increase the number of reactants

True or false. Most enzymes are proteins.

true

Enzymes function as ______________.

catalysts
-speed up chemical reactions
-lower the activation energy of the chemical reaction
-not used up in a chemical reaction
- specific to the reaction that it catalyzes
-act on specific substrate (s)

Enzyme is like a puzzle. The pieces go in a specific way.

no answer just an analogy

A substrate is_____________.

A molecule your enzymes works on to make another product.

What site does the substrate bind to?

The active site-like a handshake a tightening fit

Cofactor is another piece but it is not a ______________.

protein

The cofactor and _________ make the whole piece that fits into the ________ site.

coenzyme
alosteric site

What factors affect enzymes?

1. temperature (optimal 35-37*C)
2. pH (7 optimal)
3. substrate concentration- goes high and plateaus

Enzyme inhibitors:

Competitive - competes directly for the active site
non-competitive- competes in directly for the alosteric site
-causes active site to change shape so the the correct substrate cant bind
(eg. DDT is an inhibitor)

Stop signal of enzyme always binds to ___________ .

Enzyme 1

Allosteric site does what?

causes active site to change shape halting substrate to fit

The stop signal is the?

end product itself

Cellular respiration is ______________________?

The process by which living organisms aerobically harvest energy from food

Cellular respiration involves 3 major steps:

1. Glycolysis-breaking down of glucose
2.Kreb's cycle-removal of all energy
3.Electron Transport chain-

Glycolysis is the _____________________.

Glucose breaking down -----> pyruvic acid
produces small amounts of ATP and NADH
occurs in cytoplasm

In the Krebs's cycle two carbon acetyl groups are __________.Electrons are picked up by NAD+ and FAD for the electron transport chain.

oxidized

From one molecule of glucose, oxidation produces __ molecules of NADH, two molecules of ________ and two molecules of ___________ .

6
FADH2
ATP

Decarboxylation produces six molecules of ______ .

CO2

Electrons are brought to the ETC by __________.

NADH

The ETC consists of _______ carriers.

three

Glycolysis means______________.

splitting of sugar

One glucose molecule produces two ____ and two_____.

ATP and NADH

The end product of glycolysis is ______________.

pyruvic acid

True or false. Two molecules of ATP are invested.

true

Step 1 of glycolysis:

glucose was phosphorylated and ATP was dephosphorylated.

Step 3 of glycolysis:

Fructose-6 phosphate was phosphorylated while ATP was dephosphorylated.

True or false pyruvic acid can't enter the Krebs's cycle.

true

___________ is decarboxylated (carbon removed)and is oxidized by_________. Acetyl group is attached via a high energy bond to coenzyme A (CoA)

pyruvic acid
NAD

Krebs's cycle steps:

acetyl enters the cycle
-CoA is reused to help another acetyl enter the Krebs's cycle
Acetyl is oxidized in a series of steps
CO2 is produced (all carbon that enters exists as CO2)
NADH and FADH are produced by redox reactions

Krebs's cycle is the complete oxidation of _______.

acetyl
- pull all the energy out from acetyl ----> oxidation remove electrons.

Oxygen is highly electronegative?

true

Examples of final electron acceptors

Nitrate-E. coli and pseudomonas
Fe3+ geobacter

Chemiosmosis is the generation of _____ using the ______.

ATP
ETC

ETC is embedded in __________________.

plasma membrane

Most of the cell's ATP is produced at this stage __________ .

chemiosmosis

H+ diffuse across the membrane through ______ channels containing an enzyme ______________.

protein
ATP synthase

know this summary

Fermentation is the metabolic process used to extract energy from a sugar or other _______ molecule.

organic

True or false. Fermentation does not require the Krebs's cycle or ETC

true

Does fermentation require oxygen?

no

In fermentation the final electron acceptor is _____________.

organic

It will either produce _______ or ______________.

alcohol
acid

Does fermentation yield any ATP?

yes but in small amounts only during glycolysis

Two types of fermentation:

1. lactic acid fermentation:
-pyruvic acid-----> lactic acid (streptococcus and lactobacillus are lactic acid bacteria)
homoplactic- can only produce lactic acid
2. alcohol fermentation:
-reduced
-heterolactic (variety of products due to fermentation)