Chapter 7 : Cellular Respiration (Glycolysis, Kreb's, and ETC)
What is the net charge on NAD+?
-1
Prodcuts of the Krebs Cycle for one molecule of pyruvic acid
1 ATP, 3 CO₂, 1 FADH₂, 4 NADH
Where do the electrons come from?
10 NADH, 2 FADH₂
Does the cytoplasm have more NAD+ or NADH?
100x more NAD+ than NADH
What goes into electron transport chain?
10NADH + 2FADH₂
So how many ATP will come from citric acid cycle?
10x3=30ATP 2x2=4ATP 34ATP This the the best scenario.
Net ATP produced by KREB
2
Products of the Krebs Cycle for one molecule of glucose
2 ATP, 6 CO₂, 2 FADH₂, 8 NADH
acetyl CoA is a
2 carbon sugar conveys the carbon atoms within the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production
What is the net amount of ATP produced in glycolysis per mol of glucose?
2 mol ATP
How many ATP's are made during the Krebs Cycle?
2 net
How many ATP's are made in glycolysis?
2 net
How many total ATP'S are made by fermentation?
2 net
How many ATP's will each FADH₂ produce?
2ATP
How many ATP can be made from NADH?
3 total
How many net ATP's are made in the ETC?
32 net
How many total net ATP molecules are produced by the breakdown of 1 glucose molecule in cellular respiration?
36
How many ATP's will each NADH produce?
3ATP
KREB
4 carbon molecule **KREB has 4 letters...4 carbon molecule"
The conversion of glucose to lactate produces is equal to what percent of the ATP produced in the complete oxidation of glucose to water and carbon dioxide?
5-7%
How many steps are in the Krebs Cycle?
8
What is the Krebs Cycle
8 step pathway, step-wise catabolism of 6 carbon 6C citrate, happens twice for each glucose molecule that undergoes glycolysis
Which 2 enzymes catalyze the citric acid cycle reactions where CO2 molecules are released? (from animated interactive)
A-ketoglutarate dehydrogenase and isocitrate dehydrogenase.
What is the eventual effect of the ETC?
ATP
Is the Krebs Cycle aerobic or anaerobic?
Aerobic
What's the process that yeast cells go through to obtain energy in the absence of oxygen?
Alcoholic Fermentation
What are the two types of fermentation?
Alcoholic and Lactic Acid Fermentation.
Is glycolysis aerobic or anaerobic?
Anaerobic.
How does ATP synthase works?
As H move back into matrix ATP synthase it mechanically causes the enzyme to spin. ADP molecules are joined with Phosphate and ATP is produced. This is OXIDATIVE PHOSPHORYLATION OF ADP TO ATP :)
The Proton-Motive Force:
As H⁺ concentration increases in INTER-MEMBRANE SPACE 2 things are happening: 1) pH of the INTER-MEMBRANE SPACE lowers 2) There is a voltage difference between INTER-MEMBRANE SPACE and Matrix. These 2 things contribute to what is known as: ELECTROCHEMICAL GRADIENT. This gradient stores energy and can do work.
Steps of the Krebs Cycle
BEFORE CYCLE: CO₂ leaves (get NADH) 1: CO₂ leaves (get NADH) 2: The remaining part of pyruvic acid enters the Krebs cycle forming Citric Acid. 3: 2x CO₂ leaves 4: The cycle resets itself (get ATP, FADH₂, 3xNADH)
Why is cellular respiration called an aerobic process?
Because the process requires oxygen.
Give the chemical formula for respiration
C6H12O6+ 6 O2 --> 6 CO2 + 6 H2O + 36 ATP
What are two waste products of respiration?
CO2 and water
What is released in the Krebs Cycle?
CO2, NADH, and ATP
Which gas is released in the process of cellular respiration?
Carbon Dioxide
What process does this pathway illustrate? Glucose-------> Pyruvic acid--------->CO2 + H2O + 36 ATP
Cellular Respiration
Which 4 intermediate compounds release carbon atoms in the first round of CO2? (from animated interactive)
Citrate, Isocitrate, A-ketoglutarate, and Oxaloacetate.
When pyruvic acid first combines with the Krebs cycle, what molecule is formed?
Citric Acid
Another name for Krebs Cycle
Citric Acid Cycle
another name for Krebs cycle
Citric Acid Cycle
Where does the FADH2 go?
Electron Transport Chain
Where does the NADH go?
Electron Transport Chain
What's the process that happens after the Krebs Cycle?
Electron Transport Chain {ETC}
Where does the CO2 go?
Exhaled
How ATP will be produce?
First 2 electrons are lost! Through oxidation of NADH (NADH is oxidized): NADH→NAD⁺+H⁺+2e⁻ Second 2 electrons will be accepted by oxygen (oxygen is reduced): 2e⁻+2H+ ½O→H₂O
What molecule (substrate) does the process of glycolysis start with?
Glucose
What happens in Glycolysis?
Glucose is converted into 2 Pyruvates
Quick energy
Glycolysis is a process that produces quick or slow energy?
Name 3 stages of cellular respiration
Glycolysis, Krebs Cycle, and ETC(Electron Transfer Chain)
What is the beginning process common to both aerobic and anaerobic pathways?
Glycolysis.
What happens with the H gradient?
Hydrogens want to get back into matrix. There is a protein ATP synthase that allows H to get back into matrix.
What does O₂ become after it gets an electron?
H₂O
Where does the ATP go?
In the ATP supply
When is ATP formed in the Krebs Cycle?
In the fourth step.
When is CO2 released in the Krebs Cycle?
In the second and third steps.
When is NADH formed in the Krebs Cycle?
In the second, third, and seventh steps.
Where is the ETC located?
Inner membrane of mitochondria
Anaerobic
Is glycolysis a anaerobic or aerobic process?
What is the immediate effect of the ETC?
It creates a hydrogen concentration gradient.
What is the main benefit of alcohol fermentation?
It generates NAD+, which is necessary for glycolysis to keep producing ATP. Without it, No ATP could be produced because only NADH would be available and glycolysis can't use that.
How does the Krebs Cycle help us form lots of ATP?
It produces lots of electron carriers, in the form of NADH and FADH2, which will be used in the Electron Transport Chain to form the majority of ATP in cellular respiration.
What effect would a poison that blocks the function of ATP synthase have on the matrix of the mitochondria?
It would make the matrix accumulate H+ ions because the electron transport chain will continue pumping H+ ions into the space, but the only way they could have gotten out was through the ATP synthase- which is no longer working.
If oxygen is present, what happens after glycolysis?
Krebs Cycle
What process does this pathway illustrate? Glucose --------> 2 Lactic Acid
Lactic Acid Fermentation
What's the process that occurs in muscle cells when no oxygen is present or very low oxygen?
Lactic Acid Fermentation
In the reaction Malate + NAD+ -> Oxaloacetate + NADH which 2 items are in a reduced state? (from animated interactive)
Malate and NADH
Where does the Krebs Cycle take place?
Mitochondrial Matrix
LOCATION of KREB's CYCLE
Mitochondrial Matrix **KREB likes M&M"**
True
Most organisms are able to produce ATP through glycolysis. (TRUE or FALSE)
What is the electron/proton exchange when NAD+ becomes NADH?
NAD+ accepts 2 electrons and 1 proton
Which molecules carry high energy electrons to the ETC?
NADH & FADH2
Where do the electrons go?
Oxygen (O₂)
What is the name of the force that proton gradient creates?
PROTON-MOTIVE FORCE
Lactic Acid Fermentation
Process that produces 2 ATP in muscle cells and bacteria in the absence of oxygen.
Alcoholic Fermentation
Process that produces 2 ATP, CO2 and Ethanol in yeast when O2 is absent.
Which compound traverses the mitochondrial membrane to connect the glycolytic pathway with the citric cycle? (from animated interactive)
Pyruvate
Pre - Kreb's Cycle STEPS
Pyruvate →(NAD→NADH)→acetyl CoA + CO2 energy stored in H bond Acetyl CoA goes into Kreb's Cycle/Citric Acid Cycle
What's the starting molecule for the Krebs Cycle?
Pyruvic Acid gets converted into acetyl CoA
Write the chemical reaction for lactic acid fermentation
Pyruvic acid + NADH → lactic acid + NAD+
Anaerobic
Resipration that does not require the presence of oxygen is called?
Electron flow and complexes:
The electron transport chain is a series of oxidation/reduction reactions. NADH is electron donor and oxygen is electron acceptor. There are 4 complexes.
What is this energy used for?
The energy give off by electrons is used to pump H⁺ through the inner mitochondria membrane. Citric acid cycle happens in matrix of mitochondria. This is where all of the NADH is located. So H⁺ is pumped out of matrix into inter membrane space. We are creating gradient in here by pumping Hydrogens out. As result the other compartment becomes more acidic then matrix and there is electric gradient between the membranes.
Glycolysis
The process that breaks down glucose into ATP, NADH, and pyruvate is called?
What is the name of the folds in inner mitochondria membrane and why we need them?
They are called CRISTAE and they maximize surface area of the membrane.
How are the products of photosynthesis related to cellular respiration?
They are the reactants of cellular respiration .
How are the products of cellular respiration related to photosynthesis?
They are the reactants of photosynthesis.
The perfect number of ATP that we should produce in 30-32. However that usually does not happen. Why?
This is bc the efficiency of aerobic respiration varies from cell to cell. These differences are due the the fact that cytosolic NADH formed during glycolysis can't directly cross into mitochondria matrix. It must find alternative ways to enter mitochondria. This is called SHUTTLE MECHANISM→NADH SHUTTLES. Depending in which two shutters NADH will participate it will contribute to either 1.5ATP or 2.5ATP. Lets look at the two mechanisms.
How many times does the Krebs cycle happen for each glucose molecule?
Twice
NADH + H+
What is 10?
CO2
What is 11?
CoASH
What is 12?
NAD+
What is 13?
NADH + H+
What is 14?
CO2
What is 15?
CoASH
What is 16?
GDP + Pi
What is 17?
GTP
What is 18?
ADP
What is 19?
CoASH
What is 1?
ATP
What is 20?
FAD
What is 21?
FADH2
What is 22?
H2O
What is 23?
NAD+
What is 24?
NADH + H+
What is 25?
NAD+
What is 2?
NADH + H+
What is 3?
CO2
What is 4?
H2O
What is 5?
CoASH
What is 6?
H2O
What is 7?
H2O
What is 8?
NAD+
What is 9?
Pyruvate
What is A?
Acetyl CoA
What is B?
Citrate
What is C?
Isocitrate
What is D?
Alpha-Ketoglutarate
What is E?
Succinyl CoA
What is F?
Succinate
What is G?
Fumarate
What is H?
Malate
What is I?
Oxaloacetate
What is J?
intermediate (cis-Aconitate)
What is X?
intermediate (Oxalosuccinate)
What is Y?
ATP
What is intially needed (invested) to break glucose down?
2 ATP
What is the net gain of ATP in glycolysis?
What is so special about the electrons in NADH?
When electrons are in NADH they are in very high energy state. But then electrons will be transferred to series of transition molecules and electrons will go to much lower energy state. Bc electrons are going from high energy state to lower energy sate they give off energy on the way.
Cytoplasm
Where in the cell does glycolysis take place?
6C citrate
a Citrate with 6 carbons.
What are the categories and names of the biomolecules that serve as sources for acetyl-Coa? (from animated interactive)
acetyl-Coa are fatty acids, Amino acids, and Monosaccharides
KREB's cycle begins in the ____________ stage of cellular respiration.
aerobic **KREB does aerobics**
What are the two types of fermentation
alcoholic fermentation and lactic acid fermentation
Is fermentation aerobic or anaerobic?
anaerobic
How much ATP does the ETC make for one molecule of glucose?
approximately 30-34 ATPs
How much ATP does ALL OF RESPIRATION make for one molecule of glucose?
approximately 34-38 ATPs
Why is KREB's cyclce considered a cycle?
b/c the "4 carbon molecule" needed to start the reaction is also REgenerated in the end.
Why does a runner breathe heavily after a race?
because of the buildup of lactic acid, the chemical pathway to release this acid requires large amounts of oxygen
Why can't NAD+ or NADH cross a membrane?
both have a phosphate group added and are negatively charge compounds
What are the similarities between lactic acid and alcoholic fermentation in respiration?
both regenerate NAD+ so that glycolysis can continue
What are NADH and FADH2?
coenzymes that act as electron carriers at specific steps within the metabolism process. NADH is a product of both glycolysis and the Krebs Cycle, FADH2 is a product of the Krebs cycle
Where does glycolysis take place?
cytoplasm
What does the process of alcoholic fermentation yield
ethyl alcohol and carbon dioxide
Carbon dioxide molecules that are produced from the KREB's cycle are____________.
exhaled
Is glucose consumption in an anaerobic environment faster or slower than glucose consumption under aerobic conditions? (from animated interactive)
faster
What is the net reaction of glycolysis?
glucose+2ADP+2Pi+2NAD+ →2pyruvate+2ATP+2NADH+2H+ +2H2O
Where does the Krebs Cycle occur?
in the Mitochondrial Matrix
Where does the Krebs Cycle take place?
in the matrix of the mitochondria
Where is a high hydrogen (H+) concentration created?
intermembrane space (of mitochondria)
How does the body produce ATP during short quick bursts of energy ?
it uses ATP already in the muscles and ATP made by lactic acid fermentation
Where is a low hydrogen (H+) concentration created?
mitochondrial matrix
What is the chemical equation for alcoholic fermentation?
pyruvic acid + NADH → Alcohol + CO₂ + NAD+
What is the process by which ATP is produced in glycolysis?
substrate phosphorylation
Where does Glycolysis take place?
the Cytoplasm
What determines the charges on the phosphate groups on NAD+ and NADH?
the pH
What do the 3 flux regulation reactions in the citric acid cycle have in common? (from animated interactive)
the reactions of all of them are exergonic.
Why is oxygen required for cell respiration?
to take away electrons after the ETC (combines with H+ to make water)
