Bio Chapter 8
What is anaerobic respiration?
-Form of cellular respiration in some prokaryotes -A molecule other than oxygen, such as sulfate or nitrate, is used in the ATP-producing process
Describe what happens (to energy) in redox reactions
-In redox reactions, electrons release some of their energy as they pass from a donor molecule to an acceptor molecule -This free energy is available for cellular work, such as ATP synthesis
What is reduction?
-The addition of electrons to a substance -The substance that receives the electrons (the electron acceptor) is reduced
What is oxidation?
-The removal of electrons from a substance -The substance from which the electrons are removed (the electron donor) is oxidized
What is cellular respiration?
Collection of metabolic reactions that breaks down food molecules to produce energy in the form of ATP
What carries the two carbon fragment that are oxidized onto an acetyl group in pyruvate acid oxidation to the citric acid cycle?
a nucleotide-based carrier coenzyme A (CoA)
strict aerobes
absolutely require oxygen and cannot live on fermentation -brain cells
How are proteins broken down?
amino group is removes -enters pathway as pyruvate, acetyl coA or into the citric acid cycle
What is substrate-level phosphorylation?
an enzyme-catalyed reaction that transfers a phosphate group from a substrate to ADP
What is pyruvate?
an organic compound with a backbone of three carbon atoms
Fermentation
anaerobic respiration -electrons carried by NADH are transferred to an acceptor molecule -glycolysis continues to supply ATP by substrate level phosphorylation
What are dehydrogenase enzymes?
facilitate transfer of electrons from a fuel molecule to a molecule that acts as an electron carrier
ATP synthase
uses proton-motive force to add phosphate to ADP creating ATP (YAYAYAYAYA ENERGY!!!!)
How many cycles do we get from one glucose molecule?
2
What is aerobic respiration?
-Form of cellular respiration in eukaryotes and many prokaryotes -Oxygen is a reactant in the ATP producing process
Alcoholic fermentation
-converts pyruvate to ethyl alcohol and CO2 -occurs in plant tissue, protists, bacteria, yeasts -makes bread and alcoholic drinks
Where do electrons in the electron transfer chain go in NADH and FADH2?
-electrons from NADH enter in complex 1 -electrons from FAD enter into complex 2 -they all move through system spontaneously
Why is there a net of 2 ATP made from glycolysis?
1. first step of glycolysis, to break the glucose molecule, requires 2 ATP 2. 4 ATP are produced by substrate-level phosphorylation
What does the oxidation of pyruvate generate?
2 CO2, Acetyl-CoA (what enters the citric acid cycle) and 2 NADH
How much ATP is formed when one glucose molecule is used?
32 ATP
Total molecule numbers
6 Co2 32 ATP 10 NADH 2 FADH2
Which organisms have glycolysis?
ALL
What is the function of the mitochondria?
ATP forms in mitochondria as part of the reactions of cellular respiration
What are the carbon products transferred in the citric acid cycle to?
CO2
How does NAD+ involved in glycolysis?
NAD+ is reduced to NADH, which carries 2 electrons and a proton removed from fuel molecules
What is a redox reaction?
Reactions that remove electrons from a donor molecule and simultaneously add them to an acceptor molecule
Electron Transfer Chain where does it occur?
Series of electron carriers and pick up and release electrons to transfer them to their final acceptor---oxygen -oxidizes electron carriers to create energy that drives H+ out of membrane to create gradient -occurs in inner mitochondrial membrane
Why do some places in the body have more mitochondria?
The higher the energy demand of the structure, the more mitochondria
Why are mitochondria so special?
They can function on their own -contain own DNA
How are fats oxidized?
by glycerol and individual fatty acids
facultative anaerobes
can switch between fermentation and cellular respiration -E. coli, vertebrate and muscle cells
What are two major biological steps of the carbon cycle?
cellular respiration and photosynthesis
lactate fermentation
converts pyruvate into lactate -occurs in bacteria, plant tissues and skeletal muscle -used to make buttermilk, yogurt, pickles
Where does glycolysis occur?
cytoplasm (cytosol)
What happens to electrons in photosynthesis?
electrons from water are pushed to very high energy levels and stored (along with H+) in sugar molecules
What do electrons do in Electron Transfer Chain?
electrons release energy that is used to build H+ gradient across membrane -High H+ conc. in inner membrane -Low H+ conc. in matrix
Describe glycolysis
enzyme breaks a molecule of glucose (contains 6 carbon atoms) into two molecules of pyruvate, happens in cytoplasm and 2 ATP comes out
Describe pyruvate oxidation
enzymes convert the three-carbon pyruvate into a two carbon acetyl group that enters the citric acid cycle
chemoismosis
how the H+ gradient powers ATP synthesis by ATP synthase
Where does pyruvate oxidation and the citric acid cycle occur?
occurs in the mitochondrial matrix
Citric Acid cycle
oxidizes acetyl group completely to release 4 CO2, produces 6 NADH and 2 FADH and 2 ATP
What is the primary source of the food molecules broken down in cellular respiration called?
photosynthesis
How does cellular respiration release energy?
releases energy from electrons as they pass among acceptor molecules to a final acceptor (oxygen)
Pyruvate Oxidation
removes CO2 from pyruvate and oxidizes 2 carbon fragment to acetyl group which is carried by acetyl-CoA into citric acid cycle
strict anaerobes
require no oxygen
What is the most common electron carrier?
the coenzyme nicotinamide adenine dinucleotide (NAD+)
What does total energy gained depend on?
the difference between the high energy level in fuel and the lower energy level in the final acceptor
What does dehydrogenase do in cellular respiration?
transfer two electrons and one proton to NAD+ (the oxidized form), resulting in its complete reduction to NADH (the reduced form)
Describe the citric acid cycle
two carbon acetyl group enters and is completely oxide to 4 carbon dioxide, 6 NADH, 2 FADH2, 2 ATP
