Chapter 9- Cellular Respiration
During Glycolysis, _ molecule of glucose, a 6- carbon compound, is transformed into _ molecules of pyruvate, a 3-carbon compound
1 molecule of glucose; 2 molecules of pyruvate
How many calories are in a kilocalorie?
1000
What are the products of Glycolysis?
2 ATP's, 2 molecules of Pyruvate, 2 NADH
The end result of Glycolysis is __ molecules of a 3-carbon compound called ___ __ or ___.
2 molecules; Pyruvic Acid or Pyruvate
At the pathways beginning, __ ATP's are used up. Although _ ATP's are put in, glycolysis produces _ ATP's. this gives the cell a net gain of __ ATP's
2; 2; 4; 2
__ molecules of ATP are "invested" to get the process of Glycolysis going. Overall, _ ATP's are produced for a net gain of __ ATPS.
2; 4; 2
Cellular respiration captures the energy from food in __ main stages: Glycolysis, The Krebs Cycle, and Electron Transport Chain
3
Together, Glycolysis, the Krebs Cycle, and Electron Transport chain release about ___ molecules of ATP.
36
What is the main product of The Electron Transport Chain?
36-38 ATP
In Glycolysis, __ ATP's are synthesized from 4 ADP's. Given that 2 ATP molecules are used to start the process, there is a net gain of just 2 ATP molecules.
4
Carbohydrates and proteins contain approx. ____ calories or ____ Calories of energy per gram
4000 calories; 4 Calories
In Glycolysis, __ high energy electrons are passed to the carrier, NAD+ to produce _____.
4; NADH
As the Krebs Cycle continues, citric acid is broken down into a __ carbon molecule, more carbon dioxide is ___, and electrons are transferred to energy ___.
4; released; carriers
What are the products of the Krebs Cycle?
6 NADH , 2 FADH2 , 2 ATP , 6 CO2
Fats contain approx. ___ calories or ___ Calories per gram.
9000 calories; 9 Calories
The __ __ __ uses high energy electrons from glycolysis and the Krebs cycle to convert ___ to ___.
ADP to ATP
For each turn of the cycle, a molecule of ADP is converted to a molecule of __
ATP
Only a small amount of energy is captured to produce ___ during this stage
ATP
Since cells break down food molecules gradually, is enables cells to use the energy stored in the chemical bonds of foods like glucose to produce compounds such as ___ that directly power the activities of the cell.
ATP
The inter mitochondria membrane contains enzymes known as ___ ___.
ATP Synthases
Humans have 3 main sources of ATP. What are they?
ATP already in muscles, ATP made by lactic acid, and ATP produced by cellular respiration.
Oxygen serves as the final electron ___ of the ETC, thus ____ is essential for getting rid of low energy electrons and hydrogen ions, the wastes of cellular respiration
Acceptor; Oxygen
The other 2 carbon atoms from pyruvic acid rearrange and form ___ acid which is joined to a compound called coenzyme A.
Acetic
The resulting molecule of acetic acid and coenzyme A is ___ ___ .
Acetyl CoA
___ contribues to the sour taste in cheese, yogurt, buttermilk, and sour cream.
Acid
The Krebs Cycle and the ETC are both ___.
Aerobic
pathways that require oxygen
Aerobic
Yeasts and a few other microorganisms use this type of fermentation, which produces ethyl alcohol and carbon dioxide.
Alcoholic Fermentation
this process is used to produce alcoholic beverages and also causes bread dough to rise.
Alcoholic Fermentation
There are 2 forms of Fermentation: ___ and ___.
Alcoholic and Lactic Acid
Glycolysis is said to be ___.
Anaerobic
Pathways that do not require oxygen
Anaerobic
Fermentation is an ___ process that occurs in the ____ of cells.
Anaerobic; cytoplasm
What is the overall chemical equation for cellular respiration?
C6H1206 + 6O2 yields in the presence of enzymes 6Co2 + 6H2O + 36-38 ATP's
the amount of energy needed to raise the temperature of one gram of water, one degree celsius
Calorie
Energy stored in food is expressed in units of ___.
Calories
High energy electrons are then passed from one ___ to the next.
Carrier
For exercise longer than about 90 seconds, ___ ____ is the only way to continue generating a supply of ATP .
Cellular Respiration
If oxygen is available, organisms can obtain energy from food by what process?
Cellular Respiration
process that releases energy from food in the presence of oxygen
Cellular Respiration
What does Cellular Respiration do with carbon dioxide?
Cellular Respiration puts Carbon Dioxide back
What does Cellular Respiration do with Oxygen?
Cellular respiration uses oxygen to release energy from food
Food provides living things with the ____blocks they need to grow and reproduce
Chemical
Cells do not simply burn food and release energy as heat. Instead, they break down food molecules gradually. Because they break down food molecules gradually, is captures a little bit of ___ ___ at key steps.
Chemical Energy
For all organisms, food molecules contain ____ ____ that is released when their chemical bonds are broken.
Chemical Energy
The cell uses ____ to produce ATP.
Chemiosmosis
As the Krebs Cycle begins, acetyl CoA adds the 2 carbon acetyl group to a 4 carbon molecule already present in the cycle, producing a 6-carbon molecule called __ ___.
Citric Acid
Because __ acid is the first compound formed in the Krebs Cycle, the Krebs Cycle is also known as the Citric Acid Cycle
Citric Acid
Photosynthesis is the process that "____" energy, and Cellular Respiration is the process that "____" energy.
Deposits; Withdraws
NADH and FADH2 pass their high energy electrons to the __ __ __ .
ETC
NADH carries high energy electrons to the __ ___ __ .
Electron Transport Chain
Products from both the Krebs Cycle and Glycolysis feed into the last step of cellular respiration- the __ __ __ .
Electron Transport Chain
The bulk of the energy, however, comes from the final stage, _____ ____ _____.
Electron Transport Chain
When a cell generates large amounts of ATP from glycolysis, it runs into a problem. In just a few seconds, all of the cell's available NAD+ molecules are filled up with ____.
Electrons
Even though Glycolysis is an energy-releasing process, the cell needs to put in a little ___ to get things going.
Energy
Although the energy yield from Glycolysis is small, the process is so ___ that cells can produce thousands of ATP molecules in just a few milli seconds.
Fast
Cells use all sorts of molecules for food including what?
Fats, proteins, and carbohydrates
If oxygen is not present, other anaerobic pathways, known as _____ make is possible for the cell to keep Glycolysis running, generating ATP to power cellular activity.
Fermentation
process by which cells release energy in the absence of oxygen; the recycling of NAD+ by passing high-energy electrons back to pyruvic acid.
Fermentation
How does the cell extract the rest of that energy?
First, pyruvic acid enters the second stage, the Krebs Cycle where a little more energy is generated
Organisms get the energy they need from ___
Food
Glycolysis involves many chemical steps that transform ___
Glucose
What is the overall chemical equation in words?
Glucose and oxygen combine in the presence of enzymes to produce carbon dioxide, water and energy
During fermentation, cells convert NADH back into the electron carrier NAD+, allowing ____ to produce a steady supply of ATP.
Glycolysis
Glucose first enters a chemical pathway called ___.
Glycolysis
Without NAD+, the cell cannot keep ___ going, and ATP production stops. This is when fermentation comes in.
Glycolysis
the first set of reactions in Cellular Respiration is called...
Glycolysis
The Electron Transport chain requires reactants from what?
Glycolysis and The Krebs Cycle
Before most of the runners have passed the 50- meter mark, that store of ATP is nearly __.
Gone
Every time 2 high energy electrons pass down the chain, their energy is used to transport ___ ions across the membrane.
H+
The charge differences across the membrane forces ___ ions through channels in these enzymes, actually causing the ATP Synthases to spin.
H+
Where does Glycolysis occur?
In the cytoplasm of a cell
Anytime a cell's demand for energy increases, its use of oxygen ___.
Increases
When oxygen is available, however, pyruvic acid and NADH "outputs" generated during Glycolysis become the "___" for other processes of cellular respiration.
Inputs
How does the Electron Transport Chain extract so much energy?
It uses one of the world's most powerful electron acceptor- oxygen.
The calorie that is used in food labels is a _____
Kilocalorie
Pickles, sauerkraut, and kimono are also produced using __ __ fermentation
Lactic Acid
At this point, the runner's muscle cells are producing most of their ATP by ___ ___ ____.
Lactic Acid Fermentation
Most organisms, including us, carry out fermentation using a chemical reaction that converts pyruvic acid to lactic acid.
Lactic Acid Fermentation
The Krebs Cycle begins when pyruvic acid produced by Glycolysis passes through the two membranes of the mitochondrion and into the ___ .
Matrix
the innermost compartment of the mitochondrion and the site of the Krebs Cycle reactions
Matrix
structures in the cell that convert chemical energy stored in food to usable energy for the cell
Mitochondrion
One of the reactions of Glycolysis removes 4 electrons, now in high energy state, and passes them to an electron carrier called ___.
NAD+
electron carrier involved in glycolysis that is oxidized when G3P is reduced
NAD+
Each NAD+ molecule accepts a pair of high energy electrons. This molecule, now known as ____, holds the electrons until they can be transferred to other molecules.
NADH
Glycolysis generates high energy electrons that are passed to NAD+, forming ____ . Those NADH molecules can enter the mitochondrion, where they join NADH and FADH2, generated by the Krebs Cycle.
NADH
At 5 places, electron carriers accept a pair of high energy electrons, changing NAD+ to ____ and FAD to ____.
NADH; FADH2
Similarly, the matrix side of the membrane, from which those H+ ions have been taken, is now ___ charged compared to the inter membrane space.
Negatively
What happens to each of the Krebs Cycle products - Co2 is ____ _____ to the cell and is expelled every time you exhale. ATP are very useful and become immediately __ to power cellular activities. In the presence of oxygen, carrier molecules are used to ___ huge amounts of ATP.
Not useful; available; generate
The energy in Photosynthesis and Cellular Respiration flow in ____ directions.
Opposite
Glycolysis can quickly supply chemical energy to the cell when ___ is not available.
Oxygen
Most of the energy releasing pathways within cells require ____, and that is the reason we need to breathe.
Oxygen
When oxygen is not present, glycolysis is followed by a pathway that makes it possible to continue to produce ATP without ___.
Oxygen
Without ___, the ETC does not run, so there is nowhere for the NADH molecules to deposit their electrons. Thus, NADH does not get converted back to NAD+.
Oxygen
__ is required at the very end of the ETC.
Oxygen
Cellular Respiration is balanced by another process. What is this process called?
Photosynthesis
What does Photosynthesis do with oxygen?
Photosynthesis releases oxygen into the atmosphere
What does Photosynthesis do with carbon dioxide?
Photosynthesis removes Carbon dioxide from the atmosphere
Photosynthesis only occurs in what?
Plants, algae, and some bacteria
During electron transport, H+ ions build up in the inter membrane space, making it ___ charged relative to the matrix.
Positively
Formula for Alcoholic Fermentation
Pyruvic acid + NADH yields Alcohol + CO2 + NAD+
Formula for Lactic Acid Fermentation
Pyruvic acid + NADH yields Lactic Acid + NAD+
In glycolysis, as the bonds in glucose are broken down and rearranged, energy is ___.
Released
The equations of Photosynthesis and Cellular Respiration are the __ of each other .
Reverse
Glycolysis, however does not directly require oxygen, nor does it rely on an oxygen requiring process to ___.
Run
The elections are then passed from all those carriers to where?
The Electron Transport Chain
In the presence of oxygen, pyruvic acid in glycolysis passes to the second stage of cellular respiration: ___ ___ __ .
The Krebs Cycle
pyruvic acid is broken down into carbon dioxide in a series of energy extracting reactions
The Krebs Cycle
Which 2 processes generate the most ATP during cellular respiration ?
The Krebs Cycle and The Electron Transport Chain
Where do the Krebs Cycle and Electron Transport Chain occur?
The Mitochondrion
The cell has to release the explosive chemical energy in food molecules a little bit at a time and then needs to find a way to ___ those little bits of energy by using them to make ATP.
Trap
At the end of Glycolysis, ___% of the chemical energy that was available in glucose is still ___, locked in chemical bonds of a molecule called ____ ___.
Unused; pyruvic acid
A lot of energy is present in food, although it __ how much in the type of food.
Varies
The energy stored in each of these macromolecules (fats, proteins, and carbohydrates) ____ because of chemical structures, and therefore their energy storing bonds differ.
Varies
At the end of the ETC is an enzyme that combines these electrons with hydrogen ions and oxygen to form __.
Water
When the starting gun goes off in a footrace, the muscles of the runners contain only enough of this ATP for __ ___ ___ __ intense activity.
a few seconds of
Cellular Respiration takes place in nearly all ___: plants, animals, fungi, protists, and most bacteria.
life
Even though the Krebs Cycle does not directly use _____, it is aerobic because it cannot run without the oxygen requiring ETC.
oxygen
Cellular respiration requires ____and a ____ ____ such as glucose, and it gives off carbon dioxide, water and energy.
oxygen and a food molecule
With each spin, the enzyme grabs an ADP molecule and attaches it to a ___ ___ , producing ATP.
phosphate group
Once pyruvate is in the matrix, 1 carbon atom from pyruvic acid becomes part of a molecule of carbon dioxide, which is eventually ___ into the air.
released
Cellular Respiration releases energy more ___ than fermentation does, which is why even well-conditioned athletes have to pace themselves during a long race or over the course of a game.
slowly
Cells normally contain ___ amounts of ATP produced during Cellular Respiration.
small
