Unit Four Flashcards
Where does all of the energy on earth come from
The sun
What do plants do w energy
Through photosynthesis they convert it into chemical energy
Fundamental function of cellular respiration
Generating ATP for cellular work
Balanced chemical equation for cellular respiration
C6H12O6 + 6O2 —> 6CO2 + 6H2O + energy
Why does hydrogen atom movement represent electron transfers
Each hydrogen atom consists of an electron and a proton so where the hydrogen goes an electron goes
Oxidation
The loss of electrons
Reduction
Gain of electrons
Why do oxidation and reduction go together
Electron transfer requires both a donor and an acceptor
In cellular respiration glucose gets… and O2 gets…
Oxidized, reduced
Two key players in oxidizing glucose
Dehydrogenase and NAD+, NAD+ is a electron shuttler in redox reactions
What is NAD+ + H?
NADH
Is NADH oxidized or reduced
Reduced
O2
At end of electron transport chain. Final electron acceptor
Three main stages of cellular respiration and where they occur in cell
- Glycolysis in cytoplasmic fluid
- Citric acid cycle in mitochondria
- Oxidative phosphorylation in mitochondria and inner mitochondrion membrane
Half step
Grooming of pyruvate, between steps one and two, pyruvate decomposes, letting off CO2 and attaching to Acetyl CoA
How is sunlight energy converted to useable cell energy
Part I: photosynthesis
-captures solar energy and stores it in bonds of glucose
Part II: cellular respiration
-releases energy stored in glucose into smaller energy packers called ATP
Equation for photosynthesis
6CO2 + 6H2O —> (light) —> C6H12O6
Glucose to
Oxygen to
Oxidized to CO2
Reduced to H2O
ATP
Adenosine triphosphate
Source of energy
Used by cells to do chemical reactions
Rechargeable
How does ATP get energy and transfer energy to molecules in cells
Substrate level phosphorylation and chemiosmosis
Substrate level phosphorylation
Substrate = molecules that bind to enzyme
Molecule with phosphate group AND ADP bind to enzyme
Enzyme causes P to transfer from molecule to ADP to make ATP
Chemiosmosis
Electrochemical gradient of H+ ions causes an H+ flow through ATP synthase (enzyme/protein)
ATP synthase joins P to ADP to make ATP by harnessing power of H+ flow
ATP releases energy (P) for other molecules to do work
- Active transport
2. Movement of organelles on “cytoskeleton highway”
Cell respiration takes place in the cell’s mitochondria
100-1000s of mitochondria in each cell
2 outer membranes (sign/evidence for endosymbiosis)
Inner membrane
First one
Highly folded folks called cristae
Chemiosmosis happens here
More surface area for chemical reactions
Intermembrane space
Second one
Stores H+ to create concentration gradient
Matrix
Third one
Very inner part of mitochondrion
Locale where a series of chemical reactions strip off H+ from glucose (citric acid/krebs cycle)
Three steps of cellular respiration and what they do
Glycolysis, breaking down of glucose (cytoplasm)
Citric acid/Krebs cycle, stripping of H+ (matrix)
Oxidative phosphorylation, electron transport chain and chemiosmosis (cristae) (inner membrane)
Glycolysis
Splitting of sugar Anaerobic process (no O2 needed yet) Add two ATP to get process going Produce four ATP Two net ATP produced Series of ten chemical reactions Starts with glucose NAD+ is the uber, carries electrons from one place to another H is energy from glucose
Bacteria
Bacteria only need a little energy so use this
Humans too active, need more ATP than glycolysis makes
Glycolysis products
2 NADH, 2 pyruvate (2 C3), 2 net ATP
Glycolysis with oxygen present
Aerobic respiration, we need O2, ATP
Glycolysis with oxygen absent
Fermentation (anaerobic)
Remove H from NADH so that NAD+ can go back to glycolysis
Two types of fermentation
Alcohol fermentation and lactic acid fermentation
Pyruvate grooming
3C (pyruvate) from glycolysis (too large to enter mitochondrion)
Exhale (release) CO2
Coenzyme A goes in, functional group from cytoplasm
NAD+ to NADH, what comes out is Acetyl CoA, helps C2 get into mitochondria
Products of pyruvate grooming
NADH, CO2, Acetyl CoA
Acetyl CoA
Help C2 get into mitochondria
Citric acid cycle
2 Acetyl CoA/ because two pyruvate soldiers formed in glycolysis, two cycles happening at once
Acetyl CoA is a well connected celebrity, drops off two C and picks up more
6C bonds with Acetyl CoA, releases CoA, makes 6 carbon (citrate)
Releases 2 CO2, four carbon left
NAD+ to NADH (released)
ATP
FAD to FADH2
Redox reactions happening
Oxidative phosphorylation
Uses electron transport and chemiosmosis in mitochondria
Energy from citric acid cycle used to pump H+ into intermembrane space
Oxygen receives electrons (very electronegative)
Rotenone, consider, carbon monoxide
Blocks electron transport chain
No H+ gradient
Prevents O2 and H from binding
Oligomycin
Blocks chemiosmosis
Creates leaky H+ ions
Fermentation
Alternate respiration pathway that enables cells to produce ATP without oxygen
Metabolic pathway that generates ATP during ATP during fermentation is glycolysis, uses no O2
To oxidize glucose in glycolysis, NAD+ must be rpe sent as an electron acceptor
When under anaerobic conditions, where oxygen is not present, fermentation provides an anaerobic path for recycling NADH back to NAD+
Dehydrogenase
Regulates redox reactions
How many does one NADH yield
Maximum 3 ATP
How many does one FADH2 yield
Maximum two ATP
cell respiration
The process of breaking down “food” (glucose molecules) in the presence of oxygen, ATP molecules (cell energy molecules) are produced.
Much of it happens in the mitochondria.
glycolysis
One molecule of glucose (6 carbons) is converted into two 3 carbon pyruvic acid molecules. Glycolysis occurs in the cytosol of the cytoplasm and is considered anaerobic because no oxygen is required during this process. 2 ATP molecules needed to start the process.
4 ATP are actually produced,
2 ATP = net gain
citric acid cycle
1) Pyruvic acid (from glycolysis) is converted to Acetyl “CoA” which is broken down into carbon dioxide (CO2) in a series of energy-extracting reactions.
2) It is an aerobic process (requires O2) & is located in the mitochondrion. The inner folds called cristae increases the surface area for chemical reactions involved in cell respiration.(more ATPS made)3) For each 3-carbon pyruvic acid, 1 ATP is produced. Therefore a total of 2 ATPs are produced from one glucose.4) Protons (H+ ions) and electrons are carried by special compounds (NADH & FADH2) from Krebs Cycle for use in the Electron Transport Chain.
oxidative phosphorylation
Takes place within the mitochondria.
2) Electrons are carried & ATPs are produced: High energy electrons from Krebs cycle are passed from one “electron carrier” to the next.
Energy given off from this process permits ATP synthase located on the inner membrane to produce ATPs.
3) One glucose molecule is responsible for the gain of 34 ATP molecules from E.T.
4) Oxygen is the final electron acceptor in the chain. The O2, electrons are combined with hydrogen ions to produce H2O.Due to the proton concentration gradient produced, the protons diffuse back across the membrane to the matrix, through ATP synthase enzyme complex.
This is called chemiosmosis.
It produces 34 ATPs.
glycolysis start, end, products
starts with 1 glucose, during 2 atp and 2 nadh released, end result is 2 pyruvate
2 net atp
what goes in is also 2 adp and 2 phosphate groups (2 atp), 2 nad+
pyruvate grooming start, end, products
starts with one pyruvate, during co2 and nadh released, 2 carbon left from pyruvate combines with coenzyme a to make one acetyl CoA
0 net atp
what else goes in is nad+ and coenzyme a
citric acid cycle start, end, products
starts with one acetyl CoA, joins with four carbon after coa leaves, during 2 co2, 3 nadh, one atp, one fadh2 released
what else goes in is four carbon, 3nad+, adp + p, fad
oxidative phosphorylation start, end, products
starts with nadh and fadh2 shuttling electrons through the etc, creates h+ gradient, h+ go through inner membrane through atp synthase, gives atp synthase power, then can combine p and adp to make atp
34 net atp
Protist
Single called organism, doesn’t need oxidative phosphorylation
Final electron acceptor in anaerobic respiration, aerobic respiration
Anaerobic is NADH
Aerobic is o2
Taxis
NADH fadh2 and acetyl CoA
