Cellular repiration processes, energy and ATP Flashcards
What is Metabolism?
Chaotic chemical assembly line
The “workers” of the assembly line, enzymes and protein that make chemical reactions happen
Sum of all chemical reactions in the body. In charge of transport, repair, respond to environment
Raw, un-finished and waste materials are in constant transport, production, use and excretion
What type of energy does cellular respiration use.
Why is it important?
ATP, stored on bonds of molecules
Organisms must continually capture, store and use energy to carry out specific functions and processes
Both anabolic and catabolic reactions require ATP
What is the ATP cycle
ATP—-energy, phosphate,H20——ADP
What happens when bonds break and form?
Activation energy is used to start a reactions
When bond break and form the position of the electron changes and therefore cause. change in energy
Making bonds release energy, breaking bonds requires energy
What are the 2 types of bond energy reactions?
Exergonic reactions - energy is released (ATP-ADP+P)
Endergonic reactions - energy is absorbed
Cells use these reactions couple together
What is ATP made up of?
Ribose, adenosine base and 3 phosphate groups
How is energy released from ATP?
The terminal phosphate group breaking off
How is ATP broken down or formed
Broken down via hydrolysis reaction catalyzed by ATPase enzyme
Formed via condensation reactions during cellular respiration
How does ATP transfer energy?
ATP - ADP +P releases energy to fuel other reactions
How is ATP produced? What are the 2 ways?
Produced by Phosphorylations- adding one phosphate group (ADP phosphorylated to form ATP)
Substrate-level Phosphorylation - An enzyme is used Phosphorylate ADP, occurs in glycolysis and the CAC
Oxidative Phosphorylation- indirectly by a series of redox reactions, occurs in the electron transport train
How does ATP regenerate?
Requires energy to make energy
Endergonic reactions (needs energy) to regenerate ATP
Energy from exergonic reactions as food gets broken down
What are redox reactions?
Substances undergoing reduction and oxidation (the transfer electrons, hydrogen and/or oxygen atoms
What is oxidation?
When a substance loses 1 or more electrons or hydrogen atoms.
Gains 1 or more oxygen atom
What is Reduction?
When a substance gains 1 or more electrons or hydrogen atoms.
Loses 1 or more oxygen atom
What is a reduction agent?
The substance that provides electrons in a redox reaction
What is a oxidation agent?
The substance that accepts electrons in a redox reaction
Redox reactions involve the movement of what 2 particles in most biological reactions?
Protons (H+) and an electron
What is the relation between reactant and products in redox reactions?
The products of one reaction are the reactant of another
Food is used as fuel for ATP. What type of bonds do organic fuel molecules contain?
C-H bonds
Why are organic fuel molecules/foods good energy sources?
Have a relatively small nuclei and electrons that have a weaker pull towards a smaller nuclei
How do the electrons in C-H bond react?
They are easily pulled closer to a larger nuclei and this results in a release of energy (electronegativity)
How do oxygen molecules work compared to other molecules?
They work in the exact opposite way, the atoms form other molecules are pulled very close to the nuclei (losing potential energy)- Oxygen is very greedy-larger nuclei
The______ the valence shell of an element, the _______ those electrons have
MORE STABLE , LESS POTENTIAL ENERGY
The______ the valence shell of an element, the _______ those electrons have (opposite)
LESS STABLE, MORE POTENTIAL ENERGY
Acronyms to remember redox?
LEO says GER
(Losing Electrons Oxidizes, Gaining Electrons Reduces)
or
OIL RIG (Oxidizing is losing, Reducing is gaining)
What is controlled oxidation?
Occurs in cellular respiration, in cells controlled by a series of enzyme mediated reactions - energy is transferred to the next step/reaction and little lost to thermal energy.
Captures energy as much as possible to create ATP.
Energy harnessed from gradient, gradual release of energy and very efficient and rapid
What is rapid combustion?
All energy given off cannot be harnessed to drive metabolic reactions.
Very inefficient, rapid, O2 added in small amounts. Examples would be a campfire/marshmallows
What are Energy Carriers
Glucoses oxidizes by oxygen to form C2O and H2O enzymes call dehydrogenases
Dehydrogenases help to transfer high-energy electrons from food to molecules. Act as carriers/shuttles (NAD+ to NADH, FAD to FADH2)
Very efficient and little energy is lost to heat
What is Aerobic cellular respiration?
A series of enzyme-controlled redox reactions that convert glucose and oxygen to CO2, H2O and ATP
What are the 4 stages in aerobic cellular respiration?
1- Glycolysis
2-Pyruvate oxidation
3-Citric Acid cycle (Krebs cycle)
4- Electron transport chain (ETC)
Where does Glycolysis take place? And in what type of cells and conditions does it occur?
In all living cells, occurs in the cytoplasm in anaerobic conditions(no oxygen)
How many reactions take place in Glycolysis?
10 enzyme -catalyzed reactions
Describe the process of glycolysis
A 6 carbon glucose is split into 2 3-carbon G3Ps by the addition of 2 ATP
G3P is further oxidized to produce energy (4 ATP), 3 NADH molecules and to end the process 2 molecules of pyruvate (3 carbon)
NADH is then used in the ETC
Where does pyruvate oxidation occur?
In the matrix of the mitochondria
Describe the process of pyruvate oxidation
1 NADH converts pyruvate into acetyl-CoA ( used in ETC)
Makes 1 molecule of acetyl-CoA, 1 NADH and 1 molecule of CO2
What is another name for the citric acid cycle and where does it occur?
Also known as the Krebs cycle
Occurs in the matrix of the mitochondria
How many reactions occur in the citric acid cycle
8 enzyme catalyzed reactions to fully oxidize acetyl-CoA
Describe the Citric acid cycle
Starts with 4 carbon oxaloactate then two 2 carbon acetyl-CoA, then to 6 carbon citrate, NAD+ to NADH + CO2, then to 5 carbon, then to NAD+ to NADH + CO2, then to 4 carbon, then 1 ATP, then FAD to FADH2, then to NAD to NADH and finally back to oxaloacetate
Where does the Electron Transport Chain take place?
The inner membrane of the mitochondria
Describe the ETC process
NADH is oxidized into protein complex 1 which allows electron to enter. These electrons move from complex 1,3,4 through increasing electronegativity and electron shuttles
FADH2 is oxidized to protein complex 2 and electrons travel from complex 2,3,4
From complex 1,2,3 protons (H+) move across membrane and create a concentration gradient (potential energy)
O2 is the final acceptor of electrons, has high en located at complex 4 and produces H2O
How many ATP molecules are produced by 1 NADH and 1 FADH2?
1 NADH = 3 ATP
1 FADH2 = 2 ATP
Describe the process of Chemiosmosis
A Proton motive force is created by the concentrations of the H+ and the repelling of the protons (like charges repel)
This force allows protons to move through ATP synthase to make ATP and create water from the reduced O2 and H+
How much ATP is created at the end of ETC and Chemiosmosis?
Theoretical 36 ATP, Actual is about 32
How long does the ETC process take to complete?
About 90 seconds
Where does anaerobic cellular respiration take place and when does it occur?
Takes place in the cytoplasm
Occurs with the absence/lack of oxygen
Anaerobic cellular respiration uses glycolysis to produce what?
2 molecules of ATP from glucose
What is needed to make ATP?
Glycolysis needs to reduce NAD+ to NADH
What does glycolysis need in order for ATP and pyruvate to be produced?
A continuous supply of NAD+
How is NAD+ produced under aerobic conditions?
The oxidation of NADH in the ETC makes a continuous supply of NAD+
What happens when there is an absence of O2 in aerobic cycles?
ETC cannot occur and cannot be used to oxidize NADH
What do organisms do in the absence of O2 to oxidize NADH?
Develop alternative processes to be able to have a continuous supply of NAD+ to drive glycolysis
Where does ethanol fermentation occur and what is another name for it?
Occurs in plants, yeast and some bacteria
Also known as Alcohol fermentation
What are the 2 steps in ethanol fermentation?
Step 1 - pyruvate is converted into acetaldehyde
Step 2 - NADH is oxidized by converting acetaldehyde into ethanol
What are the final products of ethanol fermentation?
CO2, ethanol and 2 molecules of ATP (ATP formed in glycolysis)
Where does lactic acid fermentation occur and what is another name for it?
Occurs in Animal cells
Also known as lactate fermentation
What happens during the lactic acid fermentation process?
NADH is oxidized by converting pyruvate into lactic acid
What are the final products of lactic acid fermentation?
Lactic acid and 2 molecules of ATP (ATP formed in glycolysis)
