SAS #7: Biochemical Energy Production (Module) Flashcards
is the sum total of all the biochemical reactions that take place in a living organism.
Metabolism
is a series of consecutive biochemical reactions used to convert a starting material into an end product, which is either linear or cyclic.
metabolic pathway
sum total of all biochemical reaction of citric acid cycle, the electron transport chain, and oxidative phosphorylation
common metabolic pathway
2 Types of Metabolism:
is all metabolic reactions in which small biochemical molecules are joined together to form larger ones
ANABOLISM
2 Types of Metabolism:
Consumes energy.
ANABOLISM
2 Types of Metabolism:
is all metabolic reactions in which large biochemical molecules are broken down to smaller ones
CATABOLISM
2 Types of Metabolism:
Releases energy
CATABOLISM
2 Types of Metabolism:
Ex. Oxidation of glucose
ANABOLISM
2 Types of Metabolism:
Ex. Synthesis of proteins
CATABOLISM
is a cell in which the DNA is found in a membrane-enclosed nucleus.
Eukaryotic cell
Where DNA replication and RNA synthesis happens
Nucleus
Cellular boundary
Plasma membrane
the water-based material that lies between the nucleus and the outer membrane of the cell
Cytoplasm
generates of most of the
energy for a cell
Mitochondria
contains hydrolytic enzymes needed for cellular rebuilding, repair, and degradation
Lysosome
site for protein synthesis
Ribosome
Powerhouse of the cell
MITOCHONDRIA:
▪ 50% lipid and 50% protein
▪ freely permeable to small molecules.
Outer membrane
about 20% lipid and 80% protein
Inner membrane
Highly impermeable to most substances
Inner membrane
What is the interior region of the inner membrane?
Matrix
What is the region between inner and outer membrane?
intermembrane space
Folds into cristae to increase surface area
intermembrane space
small spherical knob attached to cristae
ATP synthase complexes
Site for ATP synthesis
ATP synthase complexes:
the net energy produced used for cellular reactions
ATP (Adenosine Triphosphate)
Active portion is –SH (sulfhydryl group) or as CoA-SH Derivative of Vit. B5
CoA (Coenzyme A)
Coenzyme required for redox reactions, Derivative of Vit. B2
FAD (Flavin Adenine Dinucleotide)
What is the oxidized form of FAD?
FAD+
What is the reduced form of FAD?
FADH2
Coenzyme required for redox reactions
NAD (Nicotinamide adenine dinucleotide)
What is the oxidized form of NAD?
NAD+
What is the reduced form of NAD?
NADH
Derivative of Vit. B3
NAD (Nicotinamide adenine dinucleotide)
REDOX REACTION:
hydrogen atom loss
Oxidation
REDOX REACTION:
hydrogen atom gain.
Reductio
is the biochemical process by which food molecules, through hydrolysis, are broken down into simpler chemical units that can be used by cells for their metabolic need
Digestion
What are the end product of digestion?
Carbohydrates, proteins, fats and oils
Acetyl group formation:
reaction in cytosol
glucose metabolism
acetyl group formation:
reaction in the mitochondria
fatty acid metabolism
the end product of acetyl group formation
Acetyl CoA
what are the primary products of acetyl group formation?
2-carbon acetyl units and the reduced coenzyme NADH
A cycle that occurs in the mitochondria
Citric acid cycle
Acetyl groups are oxidized to produce CO2 (which we exhale during breathing) and energy.
citric acid cycle
Some of the energy released by these reactions is lost as heat, and some is carried by the reduced coenzymes NADH and FADH2 to the fourth stage.
the citric acid cycle
Where does the electron transport chain and oxidative phosphorylation occurs?
Mitochondria
Who discovered the Krebs cycle?
Hans Adolf Krebs
take place in the mitochondrial matrix for eukaryotes and cytosol for the prokaryotes.
Krebs cycle
Oxidation (produces NADH or FADH2), and decarboxylation, (carbon chain is shortened by the removal of a carbon atom as a CO2 molecule), are steps involved.
Krebs cycle
Reactions of the Citric Acid Cycle:
carries the two-carbon degradation product of carbohydrates, fats, and proteins, enters the cycle by combining with the four- carbon keto dicarboxylate species oxaloacetate.
Step 1: Formation of Citrate
Reactions of the Citric Acid Cycle:
This results in the transfer of the acetyl group from coenzyme A to oxaloacetate, producing the C6 citrate species and free coenzyme A.
Step 1: Formation of Citrate
Reactions of the Citric Acid Cycle:
There are two parts to the reaction: (1) the condensation of acetyl CoA and oxaloacetate to form citryl CoA, a process catalyzed by the enzyme citrate synthase and (2) hydrolysis of the thioester bond in citryl CoA to produce CoA-SH and citrate, also catalyzed by the enzyme citrate synthase.
Step 1: Formation of Citrate
Reactions of the Citric Acid Cycle:
Citrate is converted to its less symmetrical isomer isocitrate in an isomerization process that involves a dehydration followed by a hydration, both catalyzed by the enzyme aconitase.
Step 2: Formation of Isocitrate.
Reactions of the Citric Acid Cycle:
The net result of these reactions is that the -OH group from citrate is moved to a different carbon atom. Citrate is a tertiary alcohol and isocitrate a secondary alcohol. Tertiary alcohols are not readily oxidized; secondary alcohols are easier to oxidize. The next step in the cycle involves oxidation.
Step 2: Formation of Isocitrate.
Reactions of the Citric Acid Cycle:
This step involves oxidation–reduction (the first of four redox reactions in the citric acid cycle) and decarboxylation.
Step 3: Oxidation of Isocitrate and Formation of CO2.
Reactions of the Citric Acid Cycle:
The reactants are a NAD+ molecule and isocitrate.
Step 3: Oxidation of Isocitrate and Formation of CO2.
Reactions of the Citric Acid Cycle:
This second redox reaction of the cycle involves one molecule each of NAD+, CoA-SH, and a-ketoglutarate.
Step 4: Oxidation of a-Ketoglutarate and Formation of CO2.
Reactions of the Citric Acid Cycle:
Two reactant molecules are involved in this step—a Pi (HPO4-2) and a GDP (similar to ADP). The entire reaction is catalyzed by the enzyme succinyl-CoA synthetase.
Step 5: Thioester Bond Cleavage in Succinyl CoA and Phosphorylation of GDP.
Reactions of the Citric Acid Cycle:
This is the third redox reaction of the cycle. The enzyme involved is succinate dehydrogenase, and the oxidizing agent is FAD rather than NAD+.
Step 6: Oxidation of Succinate.
Reactions of the Citric Acid Cycle:
The enzyme fumarase catalyzes the addition of water to the double bond of fumarate. The enzyme is stereospecific, so only the L isomer of the product malate is produced.
Step 7: Hydration of Fumarate.
Reactions of the Citric Acid Cycle:
In the fourth oxidation–reduction reaction of the cycle, a molecule of NAD+ reacts with malate, picking up two hydrogen atoms with their associated energy to form NADH+ H+. The needed enzyme is malate dehydrogenase. The product of this reaction is regenerated oxaloacetate, which can combine with another molecule of acetyl CoA (Step 1), and the cycle can begin again.
Step 8: Oxidation of L-Malate to Regenerate Oxaloacetate.
is a series of biochemical reactions in which electrons and hydrogen ions from NADH and FADH2 are passed to intermediate carriers and then ultimately react with molecular oxygen to produce water. NADH and FADH2 are oxidized in this process.
Electron Transport Chain
The enzymes and electron carriers needed for the ETC are located along the __________________.
inner mitochondrial membrane
is the biochemical process by which ATP is synthesized from ADP as a result of the transfer of electrons and hydrogen ions from NADH or FADH2 to O2 through the electron carriers involved in the electron transport chain.
Oxidative Phosphorylation
transferring protons from the matrix side of the inner mitochondrial membrane to the intermembrane space.
proton pumps
is an explanation for the coupling of ATP synthesis with electron transport chain reactions that requires a proton gradient across the inner mitochondrial membrane.
Chemiosmotic coupling
