DAT Cellular Respiration (copy)

studied byStudied by 55 people
0.0(0)
Get a hint
Hint

Glucose → ATP

1 / 27

flashcard set

Earn XP

Description and Tags

Cellular Respiration

28 Terms

1

Glucose → ATP

  1. Glycolysis

  2. Pyruvate decarboxylation

  3. TCA (Krebs cycle)

  4. Electron transport chain

<ol><li><p>Glycolysis</p></li><li><p>Pyruvate decarboxylation</p></li><li><p>TCA (Krebs cycle)</p></li><li><p>Electron transport chain</p></li></ol>
New cards
2

Glycolysis

  • Break down of glucose

  • Anaerobic (no O2)

  • 1 glucose mol. (6 Carbons) → 2 pyruvate mols. (3 Carbons)

    • 2 ATP input → 4 ATP output & 2 NADH = 2 net ATP mols. & 2 NADH

  • Occurs in cytosol (not in organelle)

  • Steps:

    1. Hexokinase: phosphorylates glucose → Glucose-6-phosphate → irreversible rxn

    2. Phosphofructokinase (PFK): phosphorylates Glucose-6-phosphate → Fructose-1,6-bisphosphate → rate limiting step

<ul><li><p>Break down of glucose</p><p></p></li><li><p>Anaerobic (no O2)</p><p></p></li><li><p><mark data-color="yellow">1 glucose mol. (6 Carbons) → 2 pyruvate mols. (3 Carbons)</mark></p><ul><li><p>2 ATP input → 4 ATP output &amp; 2 NADH = <mark data-color="red">2 net ATP mols. &amp; 2 NADH</mark></p><p></p></li></ul></li><li><p>Occurs in cytosol (not in organelle)</p><p></p></li><li><p>Steps:</p><ol><li><p><mark data-color="red"><strong>Hexokinase:</strong></mark> phosphorylates glucose → <u><strong>Glucose-6-phosphate</strong></u> → irreversible rxn</p><p></p></li><li><p><mark data-color="red"><strong>Phosphofructokinase (PFK):</strong></mark> phosphorylates Glucose-6-phosphate → <u><strong>Fructose-1,6-bisphosphate</strong></u> → rate limiting step</p></li></ol></li></ul>
New cards
3

Most oxidized form of Carbon

  • CO2

  • Waste product of cellular respiration (occurs via oxidation)

New cards
4

Oxidation rxns

  • ADP + Pi → ATP (oxidized)

  • NAD+ + FAD+ → FADH2 + NADH (oxidized)

New cards
5

Mitochondria

  • Double layered

  • Outer membrane

  • Intermembrane space: H+ build up

  • Matrix:

    • Krebs cycle → produces ATP

    • β-oxidation to break down fatty acids

  • Inner membrane: many folds to ↑ surface area → ↑ electron transport chain output

<ul><li><p>Double layered</p><p></p></li><li><p>Outer membrane</p></li></ul><p></p><ul><li><p><mark data-color="red"><strong>Intermembrane space:</strong></mark> H+ build up</p><p></p></li><li><p><mark data-color="red"><strong>Matrix:</strong></mark></p><ul><li><p><mark data-color="yellow">Krebs cycle</mark> → produces ATP</p></li><li><p>β-oxidation to break down fatty acids</p><p></p></li></ul></li><li><p><mark data-color="red"><strong>Inner membrane</strong></mark>: many folds to ↑ surface area → <mark data-color="yellow">↑ electron transport chain output</mark></p></li></ul>
New cards
6

Pyruvate decarboxylation

  • Occurs in mitochondrial matrix

  • Aerobic process

  • 2 pyruvate molecules from glycolysis transported into matrix via secondary active transport using protons (doesn’t directly use ATP)

  • 1 Pyruvate + Coenzyme A → Acetyl CoA + 1 NADH + 1 CO2

    • Pyruvate decarboxylate complex (PDC) catalyzes rxn

New cards
7

How many CO2 and NADH yield from the breakdown of 1 glucose?

2 CO2 + 2 NADH

<p>2 CO2 + 2 NADH</p>
New cards
8

TCA (Krebs cycle) / Citric Acid Cycle

  • Occurs in mitochondrial matrix

  • Aerobic process

  • 1 Acetal CoA + oxaloacetate → citrate

    • Citrate further oxidizes until oxaloacetate is formed and the cycle repeats

  • Full cycle yields: 3 NADH + 1 FADH2 + 1 GTP (ATP) + 2 CO2

New cards
9

Electron transport chain (ETC)

  • Occurs in inner membrane / cristae of mitochondria

  • Aerobic process

  • Removes e- from glucose, pyruvate and Acetyl CoA

  • Oxidative phosphorylation occurs here

  • Carrier proteins (I, II, III, IV) in inner membrane (electron acceptors): receive electrons from electron transporters (NADH, FADH2) → pump protons against [ ] gradient into intermembrane space to supply energy to ATP synthase

    • Highly acidic environment in intermembrane space

    • CoQ (Ubiquinon): can be fully oxidized and reduced during passing of electrons b/w protein complexes

      • Soluble carrier

    • Cyt C (Cytochrome C): bound to Iron atom which transfers electrons b/w Complex III and Complex IV for redox rxns

      • Protein carrier

      • Used for genetic relations

  • Final electron acceptor (after electrons have passed though all proteins): Oxygen → combines w/ H+ to form H2O

  • ATP Synthase: drives protons down the gradient towards matrix (high [ ] → low [ ]) to catalyze ADP + Pi → ATP

    • pH + Electrical Gradient: Proton Motive Force

    • If pH of intermembrane space is higher than normal → less H+ → less cellular respiration occurring

  • NADH creates more ATP (3x) than FADH2 (2x)

    • NADH pumps more protons to carrier proteins than FADH2 because NADH enters the protein complex earlier than FADH2 and it enters Complex I (FADH2 enters Complex II)

  • Total glucose produced = 36 ATP in eukaryotes and 38 in prokaryotes (no mitochondria so don’t need to pump NADH into matrix → saving 2 ATP during glycolysis)

<ul><li><p>Occurs in <mark data-color="yellow"><strong>inner membrane / cristae</strong> of mitochondria</mark></p><p></p></li><li><p>Aerobic process</p><p></p></li><li><p>Removes e- from glucose, pyruvate and Acetyl CoA</p><p></p></li><li><p><mark data-color="red"><strong>Oxidative phosphorylation</strong></mark> occurs here</p></li></ul><p></p><ul><li><p><mark data-color="red"><strong>Carrier proteins (I, II, III, IV)</strong></mark> <strong>in inner membrane (electron acceptors):</strong> receive electrons from electron transporters (NADH, FADH2) → pump protons against [ ] gradient into intermembrane space to <mark data-color="yellow">supply energy to ATP synthase</mark></p><ul><li><p>Highly acidic environment in intermembrane space</p></li><li><p><mark data-color="red">CoQ (Ubiquinon):</mark> can be fully oxidized and reduced during passing of electrons b/w protein complexes</p><ul><li><p><mark data-color="yellow">Soluble carrier</mark></p></li></ul></li><li><p><mark data-color="red">Cyt C (Cytochrome C):</mark> bound to Iron atom which transfers electrons b/w <mark data-color="yellow"><strong>Complex III and Complex IV</strong></mark> for redox rxns</p><ul><li><p><mark data-color="yellow">Protein carrier</mark></p></li><li><p>Used for genetic relations</p><p></p></li></ul></li></ul></li><li><p><mark data-color="yellow">Final electron acceptor</mark> (after electrons have passed though all proteins): <mark data-color="red"><strong>Oxygen</strong></mark> → combines w/ H+ to form H2O</p></li></ul><p></p><ul><li><p><mark data-color="red"><strong>ATP Synthase:</strong></mark> drives protons down the gradient towards matrix (high [ ] → low [ ]) to catalyze ADP + Pi → ATP</p><ul><li><p><mark data-color="yellow">pH + Electrical Gradient: <strong>Proton Motive Force</strong></mark></p></li><li><p>If pH of intermembrane space is higher than normal → less H+ → less cellular respiration occurring</p></li></ul></li></ul><p></p><ul><li><p>NADH creates more ATP (3x) than FADH2 (2x)</p><ul><li><p>NADH pumps more protons to carrier proteins than FADH2 because NADH enters the protein complex earlier than FADH2 and it enters Complex I (FADH2 enters Complex II)</p></li></ul></li></ul><p></p><ul><li><p><mark data-color="yellow">Total glucose produced = 36 ATP in eukaryotes and 38 in prokaryotes (no mitochondria so don’t need to pump NADH into matrix → saving 2 ATP during glycolysis)</mark></p></li></ul>
New cards
10

Oxidative phosphorylation

Process of ADP → ATP from NADH and FADH2 via passing of e- through various carrier proteins in the electron transport chain

New cards
11

Electron carriers

NADH and FADH2

New cards
12

What are the products of 1 Glucose molecule that has only undergone the Krebs cycle?

1 glucose → 2 pyruvate → 2 acetyl CoA → 6 NADH + 2 FADH2 + 2 GTP + 4 CO2

New cards
13

Fermentation

  • Occurs when [O2] is too low to carry out aerobic processes in mitochondria

  • NAD+ formation prioritized to form NADH

  • Alcohol fermentation

  • Lactic Acid fermentation

New cards
14

Alcohol fermentation

  • Fungi (yeast), bacteria, plants

  • Reduces pyruvate (from glycolysis) → acetaldehyde + CO2 → ethanol (by product) in a process that oxidizes NADH → NAD+

  • Acetaldehyde is the final e- acceptor from NADH

<ul><li><p>Fungi (yeast), bacteria, plants</p><p></p></li><li><p>Reduces pyruvate (from glycolysis) → <mark data-color="red">acetaldehyde</mark> + CO2  → <mark data-color="red">ethanol</mark> (by product) in a process that oxidizes NADH → NAD+</p><p></p></li><li><p>Acetaldehyde is the final e- acceptor from NADH</p></li></ul>
New cards
15

Lactic Acid Fermentation

  • Occurs in muscle cells

  • Use glycolysis to produce 2 pyruvate mols.

  • Pyruvate reduced to lactate (by-product) → oxidizes NADH → NAD+

    • Lactate (weak base) → Lactic acid (strong acid)

  • Cori Cycle: lactate from muscle cells transported into blood stream → liver → converted to glucose → blood stream → used to generate ATP through glycolysis

<ul><li><p>Occurs in muscle cells</p></li></ul><p></p><ul><li><p>Use glycolysis to produce 2 pyruvate mols.</p></li></ul><p></p><ul><li><p>Pyruvate reduced to lactate (by-product) → oxidizes NADH → NAD+</p><ul><li><p>Lactate (weak base) → Lactic acid (strong acid)</p><p></p></li></ul></li><li><p><mark data-color="red"><strong>Cori Cycle:</strong></mark> lactate from muscle cells transported into blood stream → liver → converted to glucose → blood stream → used to generate ATP through glycolysis</p></li></ul>
New cards
16

Catabolic rxns

Releases energy by breaking down large molecules into smaller molecules

New cards
17

Anabolic rxns

Requires energy to build molecules from smaller molecules

New cards
18

Cellular metabolism

Anabolic & Catabolic rxns

New cards
19

What happens if a cell does not have glucose?

  1. Uses other carbohydrates

  2. Lipids

  3. Proteins (last resort)

New cards
20
<p>Carbohydrates as a source of energy</p>

Carbohydrates as a source of energy

  • Glycogen (polysacc.): storage for glucose

    • found mainly in muscle and liver cells

  • Glycogenesis: formation of glycogen (glucose → glycogen)

  • Glycogenolysis: break down of glycogen (glycogen→glucose)

  • Glucose-6-phosphate main molecule for rxn

  • Regulated by Insulin and glucagon

  • First broken down in mouth → stomach → duodenum → small intestine

  • Disaccharides hydrolyzed into monosaccharides → converted to glucose or glycolytic intermediates

  • All cells can store glycogen but only skeletal muscle and liver cells can store large amounts

<ul><li><p>Glycogen (polysacc.): storage for glucose</p><ul><li><p>found mainly in muscle and liver cells</p><p></p></li></ul></li><li><p><mark data-color="red"><strong>Glycogenesis:</strong></mark> formation of glycogen (glucose → glycogen)</p><p></p></li><li><p><mark data-color="red"><strong>Glycogenolysis</strong></mark>: break down of glycogen (glycogen→glucose)</p><p></p></li><li><p>Glucose-6-phosphate main molecule for rxn</p></li></ul><p></p><ul><li><p>Regulated by Insulin and glucagon</p></li></ul><p></p><ul><li><p>First broken down in mouth → stomach → duodenum → small intestine</p></li></ul><p></p><ul><li><p>Disaccharides hydrolyzed into monosaccharides → converted to glucose or glycolytic intermediates</p></li></ul><p></p><ul><li><p>All cells can store glycogen but <mark data-color="yellow">only skeletal muscle and liver cells</mark> can store large amounts</p></li></ul>
New cards
21

Gluconeogenesis

  • Forming glucose from non-carbs

  • Occurs in liver and kidney

New cards
22

Why is phosphate added to a glucose molecule?

To keep the molecule w/n the cell and prevent it from diffusing out of the cell

New cards
23

Insulin

  • Endocrine hormone

  • Released by pancreas when glucose ↑

  • Triggers cells to:

    • make glycogen from glucose for storage

    • undergo glycolysis to form ATP → activates Phosphofructokinase (R.D.S)

New cards
24

Glucagon

  • Released by pancreas when glucose ↓

  • Similar to epinephrine (triggers formation of glucose)

  • Triggers cells to:

    • Glycogenolysis to form glucose

    • Inhibit glycogenesis to inhibit glycogen production

New cards
25

Lipids as a source of energy

  • Long hydrocarbon chains that are highly reduced → have more energy than carbs

  • Triglycerides: 1 glycerol backbone bound to 3 fatty acid chains

  • Lipases in adipose tissue are hormone sensitive (e.g., to glucagon)

  • Lipolysis: break down of lipids into glycerol and the fatty acids by lipase enzymes

    • Glycerol → Glyceraldehyde 3 Phosphate (DAP/G3P/PGAL) → enters glycolysis

    • Fatty acid chains activated by 2 ATPβ-oxidation of saturated FA in mitochondrial matrix (breaks 2 carbons at the β position) → 1 NADH + 1 FADH2 and 1 Acetyl CoA → citrate in Krebs cycle → 120 ATP generated

    • β-oxidation of unsaturated FA → 1 less FADH2 for each double bond

  • Lipids combine w/ soluble proteins → lipoproteins (contain Apoproteins)

    • Classified by density (fat : protein ratio)

    • B/w meals, most lipids in plasma are in the form of lipoproteins

  • Lipoproteins large and less dense when ratio is also large

    • Chylomicrons: first fat transporters to leave enterocyte and enter lacteals (small lymphatic vessels)

    • LDL (low protein density): unhealthy due to high fat content

    • HDL (high protein density): healthy cuz transport fat away from tissues → liver → cholesterol for bile → expelled during digestion

New cards
26

What carries fatty acids in blood?

Albumin

New cards
27

Lipid digestion

  • Stored as adipose tissue

  • Only broken down in duodenum:

  1. Bile released from gall bladder to emulsify fats & pancreatic lipase to break down lipids into FA chains and monoacylglycerides

  2. Absorbed into enterocytes of small intestine

  3. Reassembled into triglycerides, and then, along with cholesterol, proteins or phospholipids → packaged into chylomicrons

  4. Chylomicrons move to lymph capillary → circulatory system

New cards
28

Proteins as a source of energy

  • Excess amino acids used for energy

  • Oxidative deamination: removal of amino group to form metabolic intermediates (Acetyl CoA, pyruvate, Oxaloacetate)

    • Directly removes ammonia from AA

    • Deamination in liver

    • By-product: NH3 (ammonia) → urea → excreted as urine in mammals

      • Uric acid in insects, birds, reptiles

  • Digestion occurs in stomach: pepsin breaks down proteins into polypeptides

  • In the small intestine: trypsin breaks down specific polypeptides into amino acids

New cards

Explore top notes

note Note
studied byStudied by 7 people
... ago
5.0(1)
note Note
studied byStudied by 23 people
... ago
5.0(1)
note Note
studied byStudied by 18 people
... ago
5.0(1)
note Note
studied byStudied by 8 people
... ago
5.0(1)
note Note
studied byStudied by 37 people
... ago
4.0(2)
note Note
studied byStudied by 13 people
... ago
5.0(1)
note Note
studied byStudied by 10 people
... ago
5.0(1)
note Note
studied byStudied by 6 people
... ago
5.0(1)

Explore top flashcards

flashcards Flashcard (49)
studied byStudied by 2 people
... ago
5.0(1)
flashcards Flashcard (73)
studied byStudied by 24 people
... ago
5.0(1)
flashcards Flashcard (29)
studied byStudied by 21 people
... ago
5.0(1)
flashcards Flashcard (21)
studied byStudied by 5 people
... ago
5.0(1)
flashcards Flashcard (103)
studied byStudied by 29 people
... ago
5.0(2)
flashcards Flashcard (20)
studied byStudied by 27 people
... ago
5.0(1)
flashcards Flashcard (30)
studied byStudied by 52 people
... ago
5.0(1)
flashcards Flashcard (177)
studied byStudied by 1 person
... ago
5.0(1)
robot