Chap 4: Cellular Respiration Flashcards
Digestion
a process by which large complex organic molecules of food are disintegrated into small absorbable forms
Enzymes break the (in polysaccharides)
a (1-4) glycosidic bonds in polysaccharides
Humans lack the enzymes that break
B (1-4) and a (1-6) glycosidic bonds present in cellulose/branched amylopectin and glycogen
GLUT (Glucose Transporters) (carriers)
responsible for the absorption of most of the products of digestion
Na+ independent GLUT
GLUT (1-4)
GLUT - 1
Erythrocytes and blood-brain barrier
GLUT - 2
liver, kidney and B-cells of pancreas
GLUT - 3
Neurons
GLUT - 4
Adipose tissue
GLUT -1, GLUT -3, GLUT - 4 involved
uptake of glucose from blood
GLUT - 2 transport
glucose into or out of cells
GLUT 5 uptake
of fructose in small intestines and testes
Cellular respiration
ATP molecules into ADP molecules thus cells must continually convert ADP molecules back into ATP molecules
Cytosol
the fluid (and suspended molecules of salts, sugars, amino acids, enzymes, etc) around the organelles
Cytoplasm
the cytosol plus the organelles suspended within it (i.e. everything EXCEPT the nucleus)
(Cytosol + Organelles)
Cell =
Plasma membrane + Cytoplasm + Nucleus
Advantages of Aerobic Respiration
- Major advan. —> more energy released
- Enough energy to produce up to 38 ATP
Advantages of Anaerobic Respiration
- Lets organisms live in places where there is little or no oxygen
- Quickly produces ATP
What stage of cellular respiration evolved before the others
Glycolysis
No oxygen in Earth’s atmosphere when
3.5 to 4 billion years ago
Without oxygen
anaerobic respiration
2 or 3 b. y. a. oxygen was gradually added to the atmosphere by
Early photosynthetic bacteria;
“oxygen catastrophe” —> aerobic organisms
Breathing Respiration
physical process that allows animals/humans to come into contact with gases in the air
Cellular Respiration
chemical process that releases energy from organic compounds (food), gradually converting it into energy that is stored in ATP molecules
Relationship between cellular respiration and photosynthesis
C.R. : 6O2 + C6H12O6
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Photos. : 6CO2 + 6H2O
Photosynthesis (difference (2))
- Takes place in a chloroplast
- Light energy from the sun changes to chemical energy in glucose
Cellular respiration (difference (2))
- Takes place in mitochondria
- Chemical energy in glucose changes to chemical energy in ATP
1st pathway –> _______(releases only small amount of energy)
glycolysis
(2 net ATP)
(Glycolysis) If oxygen is present
It will lead to 2 other pathways that release a lot of energy
Kerbs Cycle & Electron Transport Chain
(Glycolysis) If oxygen is absent
2 other pathways
Alcoholic Fermentation or Lactic Acid Fermentation
All three combined make up cellular respiration
Glycolysis + Krebs Cycle + Electron Transport Chain
ATP
Adenosine Triphosphate
(Main energy currency of cells)
ATP
Adenosine Triphosphate
(Main energy currency of cells)
ADP
AMP
Adenosine Diphosphate
Adenosine Monophosphate
ATP + H2O <–>
ADP + Pi + Energy
NAD+
Nicotinamide adenine dinucleotide
(Abundant cofactor that participates in multiple aspects of cellular metabolism)
NAD+ vs NADP
NAD+ : Involved in cellular respiration/ anabolic
NADP : Involved in photosynthesis/ catabolic
FAD+
- Flavin adenine dinucleotide
- Riboflavin
- Donate electrons to electron transport chain
GTP
- Guanosine triphosphate
- Used to carry energy
- Signaling molecules
Glycolysis Process
10 reactions
Converts glucose to pyruvate
Glycolysis -
Produce :
Consumes :
Net Yield :
Produces: 4 ATP and 2 NADH
Consumes: 2 ATP
Net Yield: 2 ATP and 2 NADH
Glycolysis (alone) does not require
Oxygen
Glycolysis (stages)
*Glucose (+ATP)
Glucose-6-phosphate (6 Carbon)
*2( Glyceraldehyde 3- phosphate (3 Carbon))
*Pyruvate
To much ATP from glycolysis can cause (problems)
1) the cell’s available NAD+ molecules become filled up with electrons
2) glycolysis shuts down, cannot proceed without available NAD+ molecules
3) ATP production stops
** -ose
***-ase
**(sugar)
***(enzymes)
End of glycolysis —>
90% of chemical energy from glucose still unused
(locked in pyruvic acid)
Krebs and Electron Transport require
Oxygen
Aerobic Processes
2nd Stage of Cellular Respiration
British biochemist 1937
1st compound formed is Citric Acid
The Kerbs Cycle
2 Turns & 2 Pyruvic Acid (from glycolysis) yield
10 NADH (2 from glycolysis) (2 from glycolysis)
2 FADH2
4 ATP (2 from glycolysis)
Then cycle starts anew
**isomerization
Changes form/structure
When carbon comes out forms CO2
NAD+ comes and forms NADH
*NADH Dehydrogenase
removing hydrogen enzyme
Electron Transport Chain is embedded
In mitochondrial inner membrane
Electron Transport Chain (FADH & NADH)
Energy is used to pump protons (H+) across the membrane from the matrix to the inner membrane space
ATP synthase is a membrane-bound enzyme that uses
the energy of the proton gradient to synthesis ATP from ADP + Pi
Acetyl-CoA added to
4 carbon compound = Citric Acid (6-C)
NADH + H+ and FADH2 (from glycolysis and Krebs cycle)
deliver hydrogen atoms
Released energy harnessed
ATP by oxidative phosphorylation
1 NADH –>
1 FADH2 –>
3 ATP
2 ATP