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59 terms

Chapter 8 Biology

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where does energy come from
sun is a key source
photosynthesis
produces glucose + O2 ->respiration-> CO2H2O+ energy celles must capture

-energy in bonds of glucose
cytoplasm
where glycolysis takes place
energy stored in glucose
in bonds, all cells metabolize glucose for energy
long term and storage energy
stored in glucose and fat
short term storage energy is stored in
energy carriers
how is cell energy metabolized
Input: glucose
1) glycolysis
2)respiration if there is oxygen , fermintation if there is no oxygen
Output: energy+CO2+H2O
glucose activation
energy in
energy harvest
energy out
glycolysis
1 glucose+2ATP-> 2 pyruvate+ 2NADH+ 4ATP net energy yield to 2ATP + 2NADH
three stages of respiration
1) pyruvate is broken in matrix down releasing energy and CO2
2) high energy electrons that travel through the electron transport chain inner membrane
3) ATP is generated by chemiosmosis
Stage 1 of cellular respiration
pyruvate is broken down releasing energy and CO2, formation of acetyl CoA-> CO2 released in this prices high energy electrons + Hydrogen transfers oxygen
NAD-> NADH
krebs cycle
appears in mitcohondria
krebs consist of 1ATP,3NADH, 1FADH2
1 glucose equal _ pyruvate
two pyruvate
1pyruvate equals_
3CO2 1ATP
double energy from 1 glucose equals_
4NADH and 1FADH2
Stage 2 of cellular respiration
high energy electrons travel through the electron transport chain
- each electron carrier releases 2 electrons into ETC
definition: series of electron carriers in the inner mitochondria embedded membrane that extract energy from ATP synthesis.
how many electron carries are produced from 1 glucose
12= 10 NADH 2FADH2
Stage 2 of cellular respiration- electron transport chain: mechanism
electrons jump from one molecule to the next losing small amount of energy at each step
output of electron transport chain
the energy issued to pump hydrogen across the membrane space
- produce a concentration gradient of H+
low energy electrons and new transferred to O-> H2O
Stage 3 of cellular respiration: ATP is generated by chemiosmosis definition
the generation of ATP by the movement of hydrogen ions across a semi permeable membrane down the gradient
Stage 3 of cellular respiration: ATP is generated by chemiosmosis: mechanism:
high concentration of H+ diffuse across membrane then ATP synthesis channel
Stage 3 of cellular respiration: ATP is generated by chemiosmosis:Output
ATP
how would the rate of ATP production be affected by absence of energy?
It would stop because it needs O2 to produce H2O
Glucose breakdown
1) glycolysis
2)cellular respiration
3)pyruovate-> acetyl acid +CO2
4) krebs cycle
5) total 36 or 38 ATP
how is NAD+ replenished?
fermentation, provides alternate mechanism
anerobic
lack of O2, how energy metabolized
how can you get more energy from your muscles?
electron transport channels exercise regiment to create more mitochondria
lactic acid fermentation
high energy electrons from NADH and H+ generate the 3C lactate from pyruvate produce NAD.
6C->2x3C->2x3C
glucose->pyruvate->lactate
alcohol fermentation
high energy electrons form NADH and H generate 2C ethanol + CO2 from pyruvate
how much ATP is produced per NADH molecule?
1 NADH= 3ATP
1FADH=2ATP
ATP
primary energy carrier for cells. This energy carrier is used by almost all of the enzymes in a cell
Why do cells convert the energy stored in the bonds of glucose into energy stored in the bonds of ATP?
Glucose is not a usable energy source for most enzymes.The energy in the bonds of glucose can only be extracted by the enzymes of glycolysis and respiration. The rest of the cellular enzymes require energy in the form of an energy carrier, usually ATP.
net products of glycolysis?
two ATP, two NADH, and two pyruvate
The reaction produces four ATP, two NADH, and two pyruvate, but two ATP were used to provide activation energy.
What would happen if a cell converted all of its NAD+ into NADH?
Glycolysis would stop due to lack of a reactant.
Glycolysis requires NAD+. Storing electrons in the bonds of NADH is not an optional step
How many of the carbons originally present in glucose continue to other reactions after glycolysis?
Six carbons are left in pyruvate moleculesThe original six carbon molecules are present in two molecules of pyruvate.
Pyruvate has three carbon molecules and is taken on to respiration for further energy extraction.
For each glucose that enters glycolysis, _____ NADH enter the electron transport chain.
10
For each glucose molecule that enters glycolosis, a total of 10 NADH are produced -- 2 are produced in glycolysis, 2 are produced in acetyl CoA production, and 6 are produced in the citric acid cycle.
In cellular respiration, most ATP molecules are produced by _____.
oxidative phosphorylation

This process utilizes energy released by electron transport.
The final electron acceptor of cellular respiration is _____.
oxygen. Oxygen is combined with electrons and hydrogen to form water.
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... intermembrane space
The energy released as electrons, which have been donated by NADH and FADH2, is passed along the electron transport chain and used to pump hydrogen ions into the intermembrane space.
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
kinetic energy that is released as hydrogen ions diffuse down their concentration gradient Concentration gradients are a form of potential energy.
steps as energy is extracted from glucose during cellular respiration.
glycolysis → acetyl CoA → citric acid cycle → electron transport chain

Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.
general equation for cellular respiration?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energyCellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).
what process takes place in the cytosol of a eukaryotic cell?
glycolysis
Glycolysis, the breakdown of glucose into two molecules of pyruvic acid, takes place in the cytosol, outside the mitochondria.
In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?
mitochondrion
All of the steps of cellular respiration except glycolysis take place in the mitochondrion.
glycolysis best definition
This process splits glucose in half and produces 2 ATPs for each glucose.
citric acid cycle?
This process produces some ATP and carbon dioxide in the mitochondrion.
breaks down carbon molecules, releasing carbon dioxide and forming some ATP.
ETC
This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.
How many high-energy molecules are produced in one round of the Krebs cycle?
three NADH, FADH2, and ATP
How many of the carbons originally present in acetyl CoA continue on to respiration after the Krebs cycle?
No carbons are left, all are lost as CO2.
The two carbons originally present in acetyl become two molecules of CO2.
Where have the carbon atoms orignially present in glucose gone after the Krebs cycle has been completed?
Two were lost in acetyl CoA formation and four were lost in the Krebs cycle.
What is the net gain of energy carrier molecules from glycolysis, acetyl CoA formation, and the Krebs cycle?
four ATP, 10 NADH, and two FADH2
What occurs immediately after a cell runs out of oxygen?
The electron transport chain stops.
Oxygen is used at the end of the electron transport chain to remove used, low-energy electrons.
What is a proper description of the path of hydrogen ions during the electron transport chain and chemiosmosis?
Hydrogen ions from the matrix are pumped into the intermembrane space, then flow back into the matrix through ATP synthase.
Hydrogen ions go back and forth between the matrix and the inner membrane space.
What property of oxygen allows it to form bonds with the electrons found at the end of the electron transport chain?
Oxygen forms polar, low-energy bonds.
Highly polar bonds can be formed from very low-energy electrons, like those found at the end of the electron transport chain.
What is the purpose of fermentation?
to convert NADH back into NAD+

NAD+ is necessary to perform glycolysis.
Imagine you could inject molecules into the leg muscles of a sprinter, right before a race. Which of the following would be most useful?
NAD+, A large supply of NAD+ will allow the leg muscles to rapidly run glycolysis and avoid fermentation for a time.
Why don't we use bacteria that perform lactic acid fermentation to make bread?
because lactic acid fermentation doesn't produce a gas
Ethanol fermentation from yeast produces CO2 gas, which causes the bread to rise.
How much usable energy is produced by lactic acid fermentation?
zero ATP and zero NADH
Fermentation does not produce usable energy. It actually wastes the energy in NADH to return it to NAD+ for use by glycolysis.