Cellular Energy Flashcards
Is ATP less or more stable than ADP
Less stable because of the additional negatively charged phosphate
Cellular respiration is a _______ process?
catabolic
breaks down glucose for energy
Endosymbiotic theory?
aerobic bacteria= mitochondria
photosynthetic bacteria= chloroplasts
Mitochondria and chloroplast similarities
- They are similar in size.
- They possess their own circular DNA.
- They have ribosomes with a large & small subunit.
- Reproduce independently of host cell
- Have double membranes
Aerobic Cellular Resp. Steps
- Glycolysis
- Pyruvate oxidation
- Krebs cycle
- Oxidative phosphorylation
Where does glycolysis take place?
Cytosol
What process does not require mitochondrial enzymes
Glycolysis
Bc it occurs in the cytosol
Enzymes involved in glycolysis
Hexokinase
Phosphofructokinase
Pyruvate Oxidation Steps
- Decarboxylation (CO2 released)
- Oxidation (NAD+ to NADH)
- Coenzyme A (produces acetyl coA)
Where does the Krebs cycle occur?
Euk: mitochondrial matrix
Prok: cytosol
What steps of cellular respiration directly produce ATP? How much in each step?
Glycolysis, Krebs Cycle and oxidative phosphorylation
Glycolysis= 2 ATP
Krebs cycle= 2 GTP/ATP
Ox. phospho= 32-34 ATP
What is the ETC goal?
Regenerate electron carriers & create an electrochemical gradient to power ATP production
What is the final acceptor in the ETC
Oxygen, it gets reduced to form water via complex 4
Where are protons pumped to and from in Oxidative phosphorylation? Essentially, the ETC of cellular respiration pumps protons (H+) from where to where?
What is very acidic because of this?
- Mitochondrial matrix to intermembrane space, forming an electrochemical gradient
- Intermembrane space is highly acidic.
Is NADH more effective than FADH2? Where does it drop off electrons? What does it regenerate?
Yes, drops electrons off at complex 1 and regenerates NAD+
Where does FADH2 drop off electrons? What does it regenerate?
At complex II
Regenerates FAD
*Fewer protons are pumped due to the bypassing of complex I
What does ATP Synthase do?
Acts as a channel protein
Provides hydrophilic tunnel allowing protons to flow down electrochem. gradient
*This spontaneous movement generates energy that is used to convert ADP + Pi into ATP, a condensation reaction that is endergonic
Where does pyruvate oxidation occur?
Euk: mitochondrial matrix
Prok: cytosol
Where does oxidative phosphorylation occur (ETC)
Euk: mitochondrial inner membrane
Prok: cellular membrane
What type of reaction is aerobic respiration
Exergonic
NADH produces how much ATP
3
*NADH from glycolysis produces less
FADH2 produces how much ATP
2
How much ATP is transferred to Euk and Prok during Glycolysis to Pyruvate Ox?
Euk: 4-6 (Some ATP used for shuttle)
Prok: 6 (because NO shuttle needed!)
What type of pathway is fermenatation? What does is rely on?
Anaerobic
ONLY relies on glycolysis!!!
Where does fermentation occur?
Cytosol
What are the 2 most common types of fermentation?
Lactic acid
Alcohol
Lactic acid fermentation main function
Uses 2 NADH from glycolysis to reduce the 2 pyruvate into 2 lactic acid
Lactic acid fermentation steps
Where does this mainly occur?
- 2NADH reduces 2 pyruv. to lactic acid
- NADH is oxidized back to NAD+
- RBCs and muscle cells bc no mitochondria
What cycle is used to help convert lactate back into glucose once oxygen is available again?
Cori cycle
What does the Cori cycle do to lactate cells?
It transports the lactate to liver cells, where it can be oxidized back into pyruvate.
Alchohol fermentation main function
uses the 2 NADH from glycolysis to convert the 2 pyruvate into 2 ethanol
Alcohol fermentation steps
- 2NADH reduces 2 pyruv. to 2-ethanol
- NADH is oxidized back to NAD+
- Decarboxylation of pyruvate into acetaldehyde
- Acetaldehyde (reduced by NADH) into ethanol
Obligate aerobes
NEED Oxygen
ONLY use aerobic respiration
Obligate ANaerobes
Organism poisoned by Oxygen
Facultative anaerobes
Can do aerobic respiration, anaerobic respiration, or fermentation
Microaerophiles
ONLY aerobic respiration
Too much O2 is bad
Aerotolerant organisms
ONLY anaerobic respiration or fermentation
O2 is NOT poisonous to them
What is glycogenolysis?
the release of glucose-6-phosphate from glycogen
______, such as _____, are the most efficient at generating ATP per carbon atom.
lipids, triglycerides
Besides glucose, what are the more preferred energy sources in order from most to least?
Carbohydrates>fats>proteins
Glycogenesis
the conversion of glucose into glycogen to be stored in the liver for energy
Where is glycogen stored?
Stored in the liver and muscle cells
Beta-oxidation
- Requires energy investment!
- Free fatty acids are converted into acetyl-CoA (makes tons of ATP)
- Occurs in the mitochondrial matrix of eukaryotic cells
Lipases digest what into what
Fats into free fatty acids and alcohols through lipolysis
Adipocytes store what?
What type of enzymes do they have?
Fats (triglycerides)
Lipase enzymes (albumin/lipoprotein blood circulation release)
What are chylomicrons
Lipoprotein transport structures formed by the fusing of triglycerides w/ proteins, phospholipids, & cholesterol.
What are lacteals?
small lymphatic vessels that take fats to the rest of the body
What is the process that proteins undergo after being broken down into amino acids? What does it create?
oxidative deamination
(creates toxic ammonia)
Humans convert ammonia into what?
Urea
Glycolysis reactants
Glycolysis products
R: glucose, ATP, NAD+ and ADP/Pi
P: ATP, NADH and pyruvate
Pyruvate Ox reactants
Pyruvate Ox products
R: pyruvate, NAD+ and CoA
P: CO2, NADH and acetyl CoA
Krebs Cycle reactants
Krebs Cycle products
R: acetyl CoA, NAD+, FAD and ADP
P: CO2, NADH, FADH2 and ATP
Ox Phospho reactants
Ox Phospho products
R: NADH, FADH2, O2 and ADP/Pi
P: NAD+, FAD, H2O and ATP
Where do the protons move in aerobic respiration?
This best represents the generation of ATP because when protons (H+) move down their concentration gradient (from high to low) as they travel from the highly concentrated ______ to ________
intermembrane space to mitochondrial matrix
Beta oxidation occurs where in eukaryotic cells?
Beta-oxidation occurs in the mitochondrial matrix of eukaryotic cells
In all biosynthetic/anabolic reactions, the products are ____ ordered and have a _____ ______ when compared to the reactants.
more, decreased entropy
____ and ______ produce much less ATP per molecule of glucose than aerobic respiration.
Glycolysis and fermentation
Beta-oxidation is the process that breaks _____ acids into ______ ____ that can go into the Krebs cycle
fatty, acetyl CoA