BIOCHEM (LEC) - INTRO TO METAB AND CELLULAR RESPIRATION

______________ is the SUM of ALL chemical reactions in a living organism (the reactions are catalyzed by specific enzymes) and is a source of ENERGY for the functioning of the body

Metabolism

Series of Metabolic steps with a specified end-product is called a _____________

Metabolic pathway

Metabolic pathways can be ___________ or ________
Metabolic pathways are either ___________ or __________
Each pathway usually has an ______________ reaction to dictate the _________ of the process

linear
cyclic
anabolic
catabolic
irreversible
direction

____________ and _________ by direction are direct opposites

Catabolism
Anabolism

_____________

has this term in the word:

- lysis

-oxidation

catabolic

______________

has this term in the word:

- genesis

- synthesis

anabolic

Do you think the same exact enzymes can perform the opposite processes?

NO, because __________ enzymes must be used because each pathway must have at least _____________________, if there is none then, a ____________ will result

different
one irreversible step
futile cycle

____________________ means the pathways have no purpose, no direction, and achieve nothing

futile cycle

How do we know if the catabolic or anabolic process will dominate?

Control the _____________, often by ___________, when one process is on, the opposite must be off

irreversible steps
negative feedback

Anabolic or catabolic?

Synthesis of a protein from amino acids - ____________
Formation of a triacylglycerol from glycerol and fatty acids - ____________
Hydrolysis of a polysaccharide to monosaccharides - ______________
Formation of a nucleic acid from nucleotides - _______________

anabolic
anabolic
catabolic
anabolic

Metabolism is needed to generate ___________ or _________ that is required for all cellular processes

energy
ATP

Humans are thermodynamically _______ systems

open

Second law states that ___________ (disorder) must increase

entropy

Without continuous energy production:
- _________________

-__________________

-____________________

Homeostasis fails
Biological order collapses
Death is possible

Energy will be talked about in molecules, and ___________ is the PRIMARY ENERGY CURRENCY

ATP

Metabolism also determines:

• ____________________

• ______________________

• _____________________

Drugs behave or act by:

• _____________________

• _____________________

Drug activation and inactivation
Drug clearance and half-life
Toxicity and therapeutic response
Modifying metabolic pathways
Altering biochemical reactions

NADH = _________ ATP
FADH2 = __________ ATP
other triphosphates (ex. GTP) = _______ ATP

2.5
1.5
1

NADH and FADH2 will only become ATP after going through the __________________

electron transport chain

FAD or _______________________ is required in numerous metabolic redox reactions. It is the OXIDIZING AGENT that converts ALKANES into ALKENES

_________ is the oxidized form
_________ is the reduced form

Flavin Adenine Dinucleotide Coenzyme
FAD
FADH2

NAD or ________________________ is required in metabolic redox pathways. It is the OXIDIZING AGENT that converts SECONDARY ALCOHOLS into KETONES

Nicotinamide Adenine Dinucleotide coenzyme

___________________ involves most biomolecules. They converge at _______________ which ultimately enters the ______________

Respiration
Acetyl CoA
Citric Acid cycle

__________________ are the most commonly used materials in respiration

Carbohydrates

Classic equation for Cellular respiration: ________________ —> _______________

C6H12O6 + 6O2

6CO2 + 6H2O + ATP

What are the 4 main stages?

1. → Monomers

2. —> Acetyl CoA and NADH

3. —> CO2 and Energy

4. —> ATP

Digestion
Acetyl group formation
Citric Acid cycle
Electron Transport Chain and Oxidative Phosphorylation

_________________ defined as the BREAKDOWN of food molecules by HYDROLYSIS into simple chemical units that can be used by cells in their metabolic processes

Digestion

Carbohydrate digestion begins in the ____________

Mouth

Digestion enzymes are ____________

Hydrolases

_____________________ breaks down the alpha glycosidic bonds in starch and glycogen to produce polysaccharides and disaccharides

Salivary amylase

Only a ___________ amount of carb digestion happens in the mouth

small

Small amounts of carbohydrates are also digested in the ______________. Carbohydrates just pass through the stomach, not digested much

Stomach

Salivary alpha amylase gets ____________ by stomach ____________

inactivated
acidity

The PRIMARY SITE for carbohydrate digestion occurs in the _____________

Small intestine

_____________________ breaks down polysaccharide chains into MALTOSE

Pancreatic alpha amylase

Pancreatic alpha amylase breaks down polysaccharide chains into ___________

maltose

Final steps of digestion occurs in the outer membranes of _________________

intestinal mucosal cells

_________ = Maltose —> Glucose
_________ = Sucrose —> Glucose and Fructose
_________ = Lactose —> Glucose and Galactose

Maltase
Sucrase
Lactase

What are the 6 pathways for Carbohydrates?

1. -

2. -

3. -

4. -

5. -

6. -

Digestion
Glycogenolysis
Glycogenesis
Glycolysis
Gluconeogenesis
Pentose phosphate pathway

What are the pathway of Digestion?

1. -salivary a-amylase

2. -gastric juice

3. -pancreatic digestive enzymes

4. -maltase, sucrase, lactase

5. -active transport

Mouth
Stomach
Small Intestine
Intestinal mucosal cells
Intestinal lining

Glycolysis is also known as ____________________________

Embden-Meyerhof-Parnas pathway

________________ is the breakdown of GLUCOSE into TWO molecules of PYRUVATE. This occurs in the ______________.

It is energy producing, consists of two phases: _______________ and _______________

Glycolysis
Cytoplasm
Energy investment
Energy payoff

________________________ will proceed to payoff while _________________________ will not proceed. For DHAP to proceed, it must isomerize into GAP. So it gives a total of 2 GAP MOLECULES (everything in the payoff must be multiplied by 2)

Glyceraldehyde-3-phosphate
Dihydroxyacetone phosphate

Usually a _________ will get energy from ATP and give it to the ____________. In payoff though, it’s the opposite. The _____________ gives the phosphate and ________ is created.

The second scenario is a special case and rarely happens in most pathways. This method of ATP synthesis is called _______________________

kinase
Substrate
Substrate
ATP
Substrate-level phosphorylation

Glycolysis happens during the ________ state. The blood sugar ____________ during the 1st 2 hours

fed
increases

In GLYCOLYSIS,

• ________ ATP are produced (7 ATP is NADH is processed)

• ____________ blood sugar

• Works during __________

• Stimulated by _____________

• Irreversible steps are _____, ________, and _______

• The COMMITED STEP is ________

2
Lowers
fed state
insulin
1, 3, 10
3

___________ and _________ can also enter glycolysis

Galactose
Fructose

Irreversible steps are the _____________

Regulation points

Step 1 — Conversion of Glucose → Glucose-6-Phosphate by ______________ • Hexokinase is ______________by glucose-6-phosphate (feedback)

Step 3 – Conversion of Fructose-6-Phosphate to Fructose-1-6- bisphosphate by ____________________ . High concentrations of ______ and ________ INHIBIT enzyme activity

Step 10 – Conversion of phosphoenolpyruvate to pyruvate by _______________. Enzyme is ____________ by _________ ATP concentrations

hexokinase
inhibited
phosphofructokinase
ATP
Citrate
pyruvate kinase
inhibited
high

Glucose
Produces = ___________________
Irreversible steps = ______, ________, and __________
Committed step = ____________
Two triose phosphates = ________________ and __________________
Enzymes involved in phosphorylation = _______________
Where does glycolysis occur? ________________
What condition does our body do this? _____________

4 ATP
2 H2O
2 NADH
1, 3, 10
3
GAP
DHAP
Kinase
Cytosol
Fed state

____________ causes muscle cramps

lactic acid

Pyruvate turns into ….

For aerobic conditions: ______________
For anaerobic conditions: ________________

Acetyl CoA
Lactate

Kreb’s cycle is also known as ____________________ or ___________________

Citric acid cycle
Tricarboxylic acid cycle

________________ is a cycle that converts ACETYL-COA to TWO molecules of CO2

Citric acid cycle

The citric acid cycle takes place at the ________________. It is called the CENTRAL HUB

mitochondrial matrix

What are the 6 reactions involved in the Citric acid cycle?

1. -

2. -

3. -

4. -

5. -

6. -

Condensation
Isomerization
Oxidation
Decarboxylation
Phosphorylation
Hydration

REDUCTION of NAD+ and FAD to produce ____________ and _____________

DECARBOXYLATION citric acid to produce ______________

NADH
FADH2
carbon dioxide

CITRIC ACID CYCLE

1. Begins with __________ and ___________ —> __________ by the enzyme _________________

2. ______________ is then broken down ultimately to ______________

3. Produces ___ molecules of CARBON DIOXIDE, ___ molecules of NADH, ___ molecule of FADH2, and ___ molecule of GTP

oxaloacetate
Acetyl-CoA
Citrate
Citrate synthase
Citrate
Oxaloacetate
2
3
1
1

When one Acetyl-CoA is processed through the Citric Acid Cycle, how many times does each of the following events occur?

1. An FAD molecule is part of the reactants?
2. A CoA-SH molecule is produced
3. A dehydrogenase enzyme is needed for the reaction to occur
4. A C5 molecule is produced

1, step 6
2, Step 1 and 5
4
1 time

The Citric Acid cycle is ______________. Depends on balance of body acetyl-CoA and Oxaloacetic acid levels

amphibolic

• Citrate – ____________ synthesis

• alpha-ketoglutarate __________

• Succinyl-CoA – _____ synthesis

• OAA – ________________ and ___________

fatty acid synthesis
catabolism
heme synthesis
gluconeogenesis and nucleotide synthesis

How many ATP is produced in 1 citric acid cycle? ______

10

Electron Transport Chain is also called ___________________

Oxidative Phosphorylation

____________________ is a series of ELECTRON TRANSFERS that generates a proton gradient to fuel the synthesis of ATP.

It occurs in the ______________________.

It consists of ____ main complexes that are coupled to ___________

Electron Transport Chain
Mitochondrial membrane
4
ATP Synthase

ELECTRON TRANSPORT CHAIN

Complex I: ______________________

NADH-CoQ reductase

ELECTRON TRANSPORT CHAIN

Complex II: ______________________

Succinate-CoQ reductase

ELECTRON TRANSPORT CHAIN

Complex III: ______________________

CoQ-cytochrome c reductase

ELECTRON TRANSPORT CHAIN

Complex IV: ______________________

Cytochrome c oxidase

____________ and _________ are oxidized to NAD+ and FAD, which allows the ETC to happen in the first place (and ultimately result to ATP synthesis)

NADH
FADH2

OXIDATIVE PHOSPHORYLATION

“Series of _________________ that generates a _________________ to fuel the synthesis of ____________”

electron transfers
proton gradients
ATP

In the series of electron transfers, there is a certain flow. Each ________________ is immediately followed by another. __________ is the LAST ELECTRON ACCEPTOR.

electron acceptor
Oxygen

When protons leave the matrix into the IMS, they ___________ get back using any of the complexes from I to IV. But, they can get fluxed back to the matrix using _________________ since it actually uses the proton influx to create ATP

CANNOT
Complex V

Proton gradient generation and ATP synthesis are DIFFERENT events, but are coupled by _______________ (_________________)

Complex V
Chemiosmotic coupling

OXIDATIVE PHOSPHORYLATION

_____________ them is their way of being regulated

Coupling

The ETC will only work when ATP LEVELS are _________, and will produce ATP as a __________

The ETC will ___________ when ATP LEVELS are __________

LOW

response
slow down
high

____ hydrogen ions are needed to generate a single ATP

4

NADH goes from Complex I to IV - total of ____ H+
FADH2 goes from Complex II to IV - total of ____ H+

10
6

Glycolysis produces NADH that is lost in the cytosol. The goal is to preserve as much _________ as possible.

- Must enter the mitochondria using ___________ and the kind used depends on what part of the body is involved

atp yield

shuttles

what are the 2 shuttles?

1. - most efficient

2. -

Malate Aspartate shuttle
Glycerol phosphate shuttle

_______________________

- the type of shuttle used when there is a demand for ATP
- Efficient electron transfer (2 NADH → 2 NADH)
- Higher ATP yield
- Prominent in the LIVER, HEART, AND KIDNEY

NADH + Oxaloacetate —> Malate via _________________

Malate aspartate shuttle system
Malate dehydrogenase

_______________________

- the type of shuttle used when ATP is needed ASAP
- Fast but less efficient (2 NADH → 2 FADH2)
- LESSER ATP yield
- Prominent in the BRAIN and SKELETAL MUSCLE

NADH + DHAP—> Glycerol-3-phosphate, uses FAD dependent enzyme

Glycerol Phosphate Shuttle system