Flashcards in Ch. 6 How Cells Harvest Chemical Energy Deck (52):
Containing/requiring molecular oxygen
Lacking/not requiring molecular oxygen
Aerobic harvesting of energy from food molecules
- energy releasing chemical breakdown of food molecules, such as glucose, and the storage of potential energy in a form that called can use to perform work
What are the three phases of cellular respiration?
2) Krebs Cycle
3) Electron Transport Chain & Chemiosmosis
Why can't the cell harvest all of the energy in a useable form?
40% of glucose is turned into ATP and the rest is converted to heat.
- describes movement of electrons from donor molecules to an acceptor molecule
Loss of electrons from a substance involved in a redox reaction
Gain of electrons by a substance involved in a redox reaction
What does oxidation and reduction accompany each other?
Always together because electron transfer needs both donor and acceptor.
An enzyme that catalyzes a chemical reaction during which one or more hydrogen atoms are removed from a molecules
What is NAD+?
Nicotinamide adenine dinucleotide
- a coenzyme that assists enzymes by converting electrons (from hydrogen atoms) during the redox reactions of cellular metabolism
- oxidized molecule, ready to pick up electrons
A molecule that conveys electrons within a cell
- make up the electron transport chain
- shuttles electrons during redox reactions that release energy for ATP synthesis
What keeps electrons of the carrier molecules moving?
Affinity for electrons.
Electron Transport Chain
Synthesizes ATP by the process of chemiosmosis.
- inner membrane of mitochondria, thylakoid of chloroplast, plasma membrane of prokaryotes
The production of ATP using the energy of H+ gradients across membranes to phosphorylate ADP
- powers most of the ATP synthase
Series of protein complexes embedded in the inner membrane of mitochondria loaded with enzymes for phosphoration of ADP to ATP
- provides the port through which H+ diffuse (uses PE of concentration gradient)
The formation of ATP occurring when an enzyme transfers a phosphate group from an organic molecule to ADP
- occurring because bond holding phosphate group in substrate molecule is less stable than ATP bond
"splitting of sugar"
Multistep chemical breakdown of a molecule of a glucose into two molecules of pyretic acid.
- first step of of cellular respiration
- occurs in cytoplasmic fluid
Metabolic cycle fueled by acetyl CoA formed after glycolysis in cellular respiration
- chemical reactions complete the metabolic breakdown of glucose molecules to carbon dioxide
- occurs in matrix of mitochondria and supplies most of the NADH molecules that carry energy to electron transport carriers
What are the three steps of cellular respiration?
2) Krebs Cycle
3) Electron Transport
What are the two carriers of electron transport chain?
NADH (NAD+) and FAD (FADH2)
A compound formed between initial reactant in metabolic pathway and the final product
How many steps are there in glycolysis?
1 - 4) Preparatory & Consumer Energy Phase [consumes 2 ATP]
5 - 9) Energy Payoff Phase [Yields 4 ATP]
What is the net gain of glycolysis?
2 ATP molecules
High energy fuel molecule for Krebs Cycle
What are three ways poisons block cellular respiration?
1) Blocks the electron transport chain
2) Inhibits ATP synthesis
3) Uncouplers makes membrane of mitochondrion leak H+
Production of ethanol from glucose in which CO2 removed from pyruvic acid & NADH is oxidized to NAD+
Lactic Acid Fermentation
Lactic acid is produced when NADH from glycolysis is oxidized
Require anaerobic conditions
- O2 would mean poison
Microorganisms that makes ATP by aerobic respiration if O2, if not then fermentation
The exchange of O2 and CO2 between organism and environment
- Cellular respiration/Internal
What is general respiration?
Oxygen from air to lungs to blood, CO2 blood to lungs to air
What is cellular respiration (internal)?
It is the energy releasing break down of food molecules in cells.
- O2 + glucose -> H20 + CO2 + Energy
- occurs in mitochondria
What is metabolism? 2 types?
All chemical changes in a cell.
Breakdown of molecules, releases energy
- ex. cellular respiration
Build molecules, stores energy
Do plant cells go through cell respiration?
What is the equation for cellular respiration?
C6H12O6 + 6O2 -> 6H20 + 6CO2 + 38 ATP
Why are fats more completely reduced?
Higher hydrogen proportion. Stores more energy in a smaller space.
What is key to energy release?
Electrons of chemical bonds that move and transfer. They start with more energy and end with less.
How do cells transfer energy from glucose to ATP?
By coupling of exothermic and endothermic. Glucose will lose hydrogen to become CO2 and oxygen will gain hydrogen to become H2O
In cellular respiration, what is oxidized and reduced?
Glucose is oxidized. Oxygen is reduced.
What step of cellular respiration is both anaerobic and aerobic?
What is the equation for glycolysis?
1 glucose (6C) -> 2 Pyruvic Acid (3C)
What are the reactants of glycolysis?
Glucose, 2 ADP, 2 Phosphorus, 2 NAD+
What are the products of glycolysis?
2 pyretic acid, 2 ATP, 2 NADH
What is the net result of Krebs Cycle?
4 CO2, 2 ATP, 6 NADH, 2 FADH2
Electron Transport Chain results in how many ATP?
What substance allows for complete metabolism of glucose?
Anaerobic metabolism of glucose. No oxygen so no strong electron chain. Results in 2C or 3C and 2 ATP.
What is the evolution of energy transformation?
Chemosynthesis -> Fermentation -> Photosynthesis -> Cellular Respiration (only one to require oxygen)