Section 3: Cellular Respiration Flashcards by michael perna

This is an overall oxidative, exergonic process

Cellular Respiration

How well did you know this?

Not at all

Perfectly

What is the ΔG for cellular respiration

-686 kcal/mole

How well did you know this?

Not at all

Perfectly

This is defined as the entry of air into lungs and gas exchange between alveoli and blood

External respiration

How well did you know this?

Not at all

Perfectly

This is defined as exchange of gas between the blood and the cells, + the intracellular respiration proccess

Internal Respiration

How well did you know this?

Not at all

Perfectly

During respiration, what high energy atoms are removed from organic molecules?

What type of reaction is this?

H atoms

Dehydrogenation

How well did you know this?

Not at all

Perfectly

What is the net equation for cellular (aerobic) respiration of glucose

C6H12O6 + 6O2 –> 6CO2 + 6H2O + energy

How well did you know this?

Not at all

Perfectly

This type of respiration occurs in the presence of O2

Aerobic Respiration

How well did you know this?

Not at all

Perfectly

What are the processes of aerbobic respiration?

What is the final product?

Glycolysis, pyruvate decarboxylation

Water

How well did you know this?

Not at all

Perfectly

This is the part of aerobic respiration comprising the decomposition of glucose into pyruvate in cytosol

Glycolysis

How well did you know this?

Not at all

Perfectly

How many ATP does glycolysis use?

How much NADH produced?

How much ATP produced?

How much pyruvate produced?

2ATP used

2NADH produced

4 ATP produced

2 pyruvate produced

How well did you know this?

Not at all

Perfectly

What is the process that produces ATP during glycolysis?

Substrate level phosphorylation

How well did you know this?

Not at all

Perfectly

This part of glycolysis is defined as the direct enzymatic transfer of a phosphate to ADP, no extraneous carriers needed

Substrate level phosphorylation

How well did you know this?

Not at all

Perfectly

In substrate level phosphorylation, what enzyme phosphorylates glucose?

This is important because…

Hexokinase

The resulting can’t move out and tricks the gradient?

How well did you know this?

Not at all

Perfectly

What molecule adds the 2nd phosphate to glucose?

What is the resulting molecule?

Why is this important?

PFK (phosphofructokinase-1)

fructose 1,6-biphosphate

Because this step is reversible and commits to glycolysis, major regulatory point!

How well did you know this?

Not at all

Perfectly

After glycolysis, what occurs?

Where does this occur?

pyruvate decarboxylation

Mitochondrial Matrix

How well did you know this?

Not at all

Perfectly

What is consumed and produced in pyruvate decarboxylation?

Pyruvate is consumed

Turns into Acetyl CoA, producing 1 NADH and 1 CO2

The net result is 2 NADH and 2 CO2

How well did you know this?

Not at all

Perfectly

What enzyme catalyzes pyruvate decarboxylation?

PDC enzyme (pyruvate dehydrogenase complex))

How well did you know this?

Not at all

Perfectly

This is the last step of aerobic respiration for the pyruvate molecules produced during glycolysis

Krebs Cycle aka Citric Acid Cycle aka Tricarboxylic Acid Cycle

How well did you know this?

Not at all

Perfectly

In the Krebs cycle, _____ merges with ____ to form _____

The cycle goes with ___ intermediates

Acetyl CoA merges with oxaloacetate to form citrate

7 intermediates

How well did you know this?

Not at all

Perfectly

What is produced per turn of the Krebs cycle?

3 NADH, 1 FADH2, 1 ATP (via sub phos), and 2 CO2 are produced per turn

How well did you know this?

Not at all

Perfectly

What happens to the 2 CO2 molecules produced during the Krebs cycle in animals?

They are exhaled

How well did you know this?

Not at all

Perfectly

What is the net products produced from one molecule of glucose during the Krebs cycle?

How many CO2 produced during both glycolysis and krebs cycle?

Total 6 NADH, 2 FADH2, 2 ATP (technically GTP), 4CO2

This is because there are 2 pyruvate molecules per glucose, multiply the products per turn by 2

6 total!

How well did you know this?

Not at all

Perfectly

How is the ATP produced in the Krebs cycle?

Substrate level phosphorylation

How well did you know this?

Not at all

Perfectly

Where does the citric acid cycle take place?

In the mitochondrial Matrix

How well did you know this?

Not at all

Perfectly

What occurs after the Krebs cycle in aerobic respiration? Where does it occur

The Electron Transport chain At the inner membrane/cristae of the mitochondria

What do the cristae (folds) do for the mitochondria and the ETC?

Increase surface area for more ETC action

This is the process of converting ADP to --> ATP from NADH and FADH2 in the ETC via passing of electrons through various carrier proteins.

oxidative phosphorylation

Where does the energy come from in the ETC?

Electrons in the ETC establishing an | H+ gradient that supplies energy to ATP synthase

Which makes more energy, NADH or FADH2?

NADH, more H+ is pumped across per NADH (3:2 yield)

What is the final electron acceptor in the ETC?

Oxygen

What does the final electron acceptor (oxygen) form?

H2O, it combines with native H+

In the ETC, carrier proteins extract energy from NADH and FADH2 while pumping protons into the intermembrane space, what uses this gradient to make atp? Where does it shuttle the H+ to?

ATP synthase (the gradient is both a pH and electrical) Back into the inner matrix

This is a soluble carrier dissolved in the membrane that can be fully reduced/oxidized, it passes electrons through the membrane in the ETC

Coenzyme Q/Ubiquinone

This is a protein carrier in the ETC, common in many living organisms, used for genetic relation They have non protein parts for ____ reactions

Cytochrome C Redox reactions

This process of the ETC couples exergonic flow of electrons with endergonic pumping of protons across the cistae membrane

Oxidative Phosphorylation

What is the total energy released from glucose in cellular respiration in eukaryotes? How much in prokaryotes?

~36 ATP ~38 ATP

What accounts for the difference in total energy released from one molecule of glucose in prokaryotes and eukaryotes?

Prokaryotes have no mitochondria so they don't need to transfer pyruvate to the mitochondrial matrix (requires active transport), they use the cell membrane for respiration

Where does cellular respiration occur in prokaryotes?

The cell membrane

This organelle has an outer membrane, intermembrane space (H+), inner membrane (ox. phosph) mitochondrial matrix (krebs)

Mitochondrial matrix

This is the mechanism of ATP generation in the mitochondria that occurs when energy is stored in the form of a proton concentration gradient across a membrane

Chemiosmosis

Krebs produces ______ and _____ , they are oxidized (lose electrons), H+ transported from matrix to __________ _______, pH and electric charge gradient is created, ATP synthase uses the energy in this gradient to create _____ by letting the protons flow through the channel

NADH, FADH2 Intramembrane space ATP

increases H+ cxn INCREASES/DECREASES pH

Decreases pH

ATP is a DNA/RNA nucleotide What type of sugar does it have?

RNA nucleotide Ribose (like RNA and DNA)

Is ATP stable or unstable? Why?

Unstable because the 3 phosphates are all negatively charged so they repel one another

In ATP, a phosphate group is removed via ____ rxn This creates a LESS/MORE stable ADP molecule This releases or absorbs energy?

Hydrolysis More stable Releases energy (exergonic)

This molecule provides energy for all cells by transferring one of its phosphates to another molecule

ATP

What are the two processes of anaerobic respiration?

Glycolysis and fermentation

Aerobic respiration regenerates NAD+ via ___, which is required for continuation of glycolysis

Without O2 in glycolysis during anaerobic respiration, there would be no replenishing ______ accumulates, the cell would die with no ATP, so ______ occurs

NADH accumulates Fermentation

This process occurs in plants, fungi (yeasts) and bacteria (botulinum) It converts pyruvate to acetaldehyde and CO2, Acetaldehyde is then converted to ______ And NADH--->

Fermemntation Ethanol NAD+

What is the final electron acceptor in anaerobic respiration? What does this form?

Acetaldehyde Ethanol (similar to O2 being electron acceptor and forming H2O)

This type of anaerobic respiration occurs in human muscle cells and other microorganisms

Lactic Acid Fermentation

In lactic acid fermentation, pyruvate is converted to

Lactate (and NADH--> NAD+)

In lactic acid fermentation, lactate is transported back to the liver for conversion back to _____ once surplus ATP is available

Glucose

These anaerobes can tolerate oxygen presence but don't use it These cannot live in the presence of oxygen These can grow with or without oxygen because they can metabolise energy aerobically and anaerobically

Aerotolerant anaerobes Obligate anaerobes Facultative Anaerobes

When glucose supply is low, body uses other energy sources, in the priority order of: These substances are first converted to ___ or ___ intermediates, then decraded in ____ or _____

other carbs, fats, and proteins Glycolysis or CAC

We don't just break down glucose, we can produce it. This process is called Where does it occur in the body?

Gluconeogenesis Liver and Kidney

What organ is responsible for maintaining glucose cxn in the blood?

The liver

This is a glucose polymer, important in the storage of glucose What amount of glycogen is stored in the liver? The kidney?

Glycogen 2/3 in liver 1/3 in kidney

____ after large meals stores glucose as glycogen ____ has the opposite effect and turns on glycogen

Insulin Glucagon

What enzyme does insulin activate/glucagon inhibits it?

PFK enzyme

Disaccharides are converted into ____, most of which can be converted to glucose or glycolytic intermediates

Monosaccharides

All cells in the body are capable of producing and storing glycogen but only ____ cells and especially __ cells have large amounts

Muscle cells and liver cells

Fats store MORE/LESS energy than carbohydrates per carbon This is because the carbons in fats are in a MORE/LESS reduced state

More energy more reduced

Triacylglycerides are converted by ______ in the lumen of small intestine to....

Lipases Monoacylglycerides and fatty acids

Where are the lipases located in the body that convert triacylglycerides to monoacylglycerides and fatty acids

Lumen of the small intestine

The monoacylglycerides broken down by lipases are absorbed in the surface ___ cells There, they are reformed into _______ These are packed into ____ particles packaged with ____ This creates ___ tissue for storage

Intestinal Triacylglycerides Chylomicron particles packaged with cholesterol Adipose tissue

Adipose tissue is broken down by _______ which creates ____ and _____

Lipases Glycerol and fatty acids

In the breakdown of adipose tisue, glycerol goes to the ______ for _____ or ______ Fatty acids are converted to _____ which goes to other tissue cells, to the __ organelles. It enters the ___ cycle

liver for glycolysis or gluconeogenesis Acetyl CoA, goes to mitochondria of cells and enters the CAC cycle

Lipases in adipose tissue are sensitive to _____

hormones (ex: glucagon)

Glycerol in adipose tissue is converted into ___ which enters glycolysis

PGAL (glyceraldehyde 3 phosphate)

When fatty acids are converted to acetyl CoA, every ___ carbon from fatty acid chain makes an Acetyl CoA

Every 2 carbons

Fatty acids in the blood combine with ____ which carriers them

Albumin

Fatty acids are broken down for energy via ________ This takes place in the __________ How many ATP are spent activating the entire fatty acid chain?

Beta oxidation Mitochondrial Matrix 2 ATP

In fatty acid metabolism, how much NADH and FADH2 does every cut into 2 carbons in SATURATED fatty acids produce? Therefore, an 18C chain is 9 2C pieces, how many times is it cut?

1 NADH, 1 FADH2 (1 of each) 8 times! tricky business. 9 fragments formed from 8 cuts

How much less FADH2 is produced for each double bond in saturated fatty acids than saturated fatty acids?

1 less FADH2

Note: fatty acid metabolism results in BIG yield of ATP , yields more ATP per carbon than carbohydrates, more energy in fats than sugars

This is the least desirable source of energy, it's only used when carbs and fat are unavailable

Protein

Most amino acids undergo _____ in the liver

deamination

Amino acids are deminated in the _______ organ

Liver

After AAs undergo deamination, they are converted to _____ or _____ or other CAC intermediates, enter cellular respiration at these various points (varies by AA)

Pyruvate or Acetyl CoA

Oxidative deamination removes _____ molecules directly from AAs.

Ammonia

Ammonia, released after deamination of AAs, is _______ to vertebrates Fish excrete it, insects and birds convert in to uric acid, mammals convert to urea for excretion

Toxic