Chapter 9 Respiration- Biology
Terms in this set (58)
Where do organisms get energy?
Organisms get the energy they need from food
Food provides living things with the chemical building blocks they need to ____________and reproduce
Food provides living things with the chemical building blocks they need to grow and __________________
Food molecules contain _______________________ that is released when its chemical bonds are broken
Energy stored in food is expressed in units of
A calorie is
The amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius
Cells break down food molecules gradually and use the energy stored in the chemical bonds to produce compounds such as _______________ that power the activities of the cell.
What is cellular respiration?
Cellular respiration is the process that releases energy from food in the presence of oxygen
If oxygen is available, organisms can obtain energy from food by a process called ________________________
Oxygen + Glucose Carbon dioxide + Water + Energy
6 O2 + C6H12O6 -> 6 CO2 + 6 H2O + Energy
The three main stages of cellular respiration are
Glycolysis, Krebs cycle, and electron transport chain.
Most of glucose's energy (90%) remains locked in the chemical bonds of ______________________ at the end of glycolysis
During the __________________, a little more energy is generated from pyruvic acid
The _____________________ produces the bulk of the energy in cellular respiration by using oxygen, a powerful electron acceptor.
Electron transport chain
Pathways of cellular respiration that require oxygen are called __________________
The Krebs cycle and electron transport chain are both aerobic processes. Both processes take place inside ____________________
Gylcolysis is _________________ process
Glycolysis takes place in __________________ of a cell
Glycolysis generates ___________ ATPs per glucose molecule
Glycolysis generates ___________ NADHs per glucose molecule
Photosynthesis removes ___________________ from the atmosphere, and cellular respiration puts it back.
Photosynthesis releases ______________________ into the atmosphere, and cellular respiration uses that oxygen to release energy from food.
What happens during the process of glycolysis?
1 molecule of glucose, is transformed into 2 molecules of pyruvic acid.
_____________________ is the first stage of cellular respiration.
Pyruvic acid is a reactant in the _____________________
____________and _____________ are produced as part of the process.
ATP and NADH
The cell uses ______________________ to get glycolysis going
2 ATP molecules
Glycolysis then produces 4 ATP molecules, giving the cell a net gain of _________ molecules for each molecule of glucose that enters glycolysis
During glycolysis, the electron carrier NAD+ (_______________________________________) accepts a pair of high-energy electrons and becomes NADH
Nicotinamide Adenine Dinucleotide
During glycolysis, the electron carrier NAD+ (Nicotinamide Adenine Dinucleotide) accepts a pair of high-energy electrons and becomes __________
NADH carries the high-energy electrons to the _________________________, where they can be used to produce more ATP.
Electron transport chain
Advantages of glycolysis
Glycolysis produces ATP very fast and It doesn't require oxygen
What happens during the Krebs cycle?
Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
During the Krebs cycle _______________of cellular respiration, pyruvic acid produced in glycolysis is broken down into carbon dioxide in a series of energy-extracting reactions.
The second stage
During the Krebs cycle the second stage of cellular respiration, pyruvic acid produced in glycolysis is broken down into __________________ in a series of energy-extracting reactions.
The Krebs cycle is also known as ___________________ because citric acid is the first compound formed in this series of reactions
Citric acid cycle
Pyruvic acid from glycolysis enters the ______________, the innermost compartment of the mitochondrion.
Once pyruvic acid is in the mitochondrial matrix, NAD+ accepts 2 high-energy electrons to form _____________.
Once pyruvic acid is in the mitochondrial matrix, NAD+ accepts 2 high-energy electrons to form NADH.The remaining 2 carbon atoms react to form_______________
Energy released by the breaking and rearranging of carbon bonds is captured in the forms __________, ____________and ___________.
ATP, NADH, and FADH2.
The electron carriers NAD+ and FAD each accept pairs of high-energy electrons to form NADH and FADH2. NADH and FADH2 are used in the ________________________ to generate ATP
Electron transport chain
How does the electron transport chain use high-energy electrons from glycolysis and the Krebs cycle?
The electron transport chain uses the high-energy electrons from glycolysis and the Krebs cycle to convert ADP into ATP
At the end of the electron transport chain, the electrons combine with H+ ions and oxygen to form ________________
H+ ions pass back across the mitochondrial membrane through the ATP synthase, causing the ATP synthase molecule to spin. With each rotation, the ________________________ attaches a phosphate to ADP to produce ATP
In the presence of oxygen, the complete breakdown of glucose through cellular respiration results in the production of ____________________
36-38 ATP molecules.
How do organisms generate energy when oxygen is not available?
In the absence of oxygen, fermentation releases energy from food
molecules by producing ATP.
_______________________ is a process by which energy can be released from food molecules in the absence of oxygen. Fermentation occurs in the cytoplasm of cells.
Under _______________________conditions, fermentation follows glycolysis.
During fermentation, cells convert NADH produced by glycolysis back into __________________________, which allows glycolysis to continue producing ATP.
into the electron carrier NAD+,
Yeast and a few other microorganisms use alcoholic fermentation that produces ____________________________________.
Ethyl alcohol and carbon dioxide
Alcoholic fermentation - chemical equation:
Pyruvic acid + NADH -> Alcohol + CO2 + NAD+
Lactic acid fermentation - chemical equation
Pyruvic acid + NADH -> Lactic acid + NAD+
________________ fermentation can supply enough ATP to last about 90 seconds.
Following intense exercise, a person will huff and puff for several minutes in order to pay back the built-up ________________ and clear the lactic acid from the body.
For intense exercise lasting longer than 90 seconds, ___________________ is required to continue production of ATP.
The body stores energy in the form of the _____________________________.
These glycogen stores are enough to last for _________________________ of activity.
15 to 20 minutes
Hibernating animals like this brown bear rely on _______________ for energy when they sleep through the winter.