Energy for Muscle Contraction Flashcards
Term used to describe all biochemical events occurring in the body at any given point in time. Consists of energy being used during these events
Metabolism
Term for smaller molecules becoming larger molecules. Like AAs becoming proteins, fatty acids become phospholipids
Prominent in growth and devlopment
Anabolism
Break down of larger molecules into smaller . Glucose –> carbon, digestion
Catabolism
A colelction of catabolic events involved in the breakdown of food products in cells which are required to produce ATP, building blocks of cell too. Primary role is to generate ATP
Cellular (Internal) Respiration
The process of energy containing nutrients starting with the digestion passing to blood then tissue. In cells of tissue, the nutrients are metabolised to build up or break down molecules.
Finally, remainder are broken down in mitochondria into ATP.
Metabolic Flow
Another place other than food to acquire energy
Existing stores of energy in body
One of 3 types of reactions. This one O2 and H atoms are involved.
Oxidation Reduction
OR reaction involving gain of O2 or loss of H atoms/electrons
Oxidation
OR reaction involving loss of O2 or gain of H atoms/electrons
Reduction
Energy is ______ in the oxidized substance, ____ by the reduced substance
Lost in oxidized substance
Gained in reduced substance
Enzymes that perform redox reactions
dehydrogenases, oxidases
Two main cofactors of redox reactions
NAD+
FAD+
What do these cofactors do?
Transfer energy from one compound to another during redox
What are NAD+ and FAD+ derivitives of? (3 things)
B vitamins - NAD
Niacin and riboflavin - FAD
Phosphorylation means….
Activate something
One of three types of reactions involving direct enzymatic phosphorylation, typically involved in formation of ATP
Substrate phosphorylation
X-P + ADP –>
X + ATP
Where is the energy?
Phosphate bond
Another reaction to phosphorylate or activate something, most ATP made this way.
Occurs in mitochondrian through electron transport chain, multi step process
Indirect phosphorylation that involves oxygen
Oxidative Phosphorylation
Term for a mechanism of ATP without using oxygen being used
Anaerobic Sources
Myosin head ATP, already stored there. Sort of but not really anaerobic
Stored ATP
Substrate level phosphorylation that is anaerobic
Creatine-P + ADP –> ATP + Creatine.
One of the quickest form of energy that occurs in cytosplasm of skeletal muscle
Creatine Kinase
Pathway that produces ATP involving glucose breakdown
Glycolysis
Creatine kinase occurs in
Glycolysis occurs in
Cytoplasm/Sarcoplasm
Cytoplasm
Chemical product of glycolysis that is untapped energy? (How many?)
2 pyruvates (pyruvid acid)
How much ATP, or in other words, immediate energy from glycolysis?
2 ATP
How much reduced forms of NAD+, or energy being transferred from glycolysis?
2 reduced forms of NAD+
Glucose is only partially oxidized
Some extracted to make atp, some in pyruvates, some extracted by NAD to be trasnferred somehwere else
!!
First phase of glycolysis where 2 ATPs are invested, converting glucose to fructose and phosphorylate (phosphorylation)
Energy used to active glucose
sugar activation
Step 2 of glyoclysis that breaks down 6 carbon molecule into 2,3 carbon molecules, each carrying phosphate.
No ATP extracted, no energy extracted
Sugar Cleavage.
Third phase of glycolysis where each 3 C molecule is oxidized by REMOVING H ATOMS and transferring them to NAD + (NADH H+)
4 ADP are phosphorlated to ATP, 2 net ATP gained
Oxidation and ATP formation
Review summary of Glycolysis Pathway in book. Don’t memorize substrates/products but know different phases and the outcome of them.
Know products of glycolysis (2 ATP, etc)
Know reduced substances (H atoms)
2 pyruvic acids
!
The remaining oxidation of the glucose molecule is performed where?
Mitochondria
First step is conversion of pyruvate to acetyl CoA (2 molecules)
Mitocholdrial Aerobic Respiration
3C pyruvate -> 2C (Acetyl CoA); release CO2, generate NADH +H+
Mitochondrial Aerobic Respiration
Where is CO2 sent?
Bloodstream for exhalation
2nd aerobic phase, where acetyl CoA (2C) is broken down completelely to yield
3 NADH +H+, reduced cofactor x2 = 6
1FADH2 reduced cofactor x 2 = 2
1 ATP x 2 = 2
Krebs Cycle
Location of krebs cycle
Mitochondrial Matrix
What is located in the mitochondrial matrix that facilitates reactions?
Enzymes
Just know where it occurs and what products are received out of the Krebs cycle
!
Substrates and products DON’T go around in a circular fashion.
!
Final oxidation step that extracts energy from reduced compounds (FADH and NADH) and synthesizes ATP
Splits H atom into proton and e- (breaks H bond)
Clusters of redox enzymes located on inner mitochondrial membrane
Uses O2
Electron Transport Chain
Electron Transport Chain is located in the _____ which is outside the mitochondrial matrix
Inner mitochondrial membrane
The NADH could have come from Krebs cycle or
Glycolysis
NADH and FADH are oxidized meaning…
H atoms are removed
What happens to the H atoms?
split into e- and H+ (proton)
electrons are passed down the chain of redox enzymes, energy from electron is used to
pump protons into intermembrane space
What is created by the passing of electrons down the chain of redox enzymes?
A Battery (Polarity)
In the membrane there is these molecules which uses energy from diffusion to synthesize ATP (from ADP and inorganic phosphate from other mechanisms) as H+ diffuses across the membrane.
ATP synthase enzymes
While ATP synthase synthesizes ATP and protons move into mitchondrial matrix from intermembrane space, need to find a way to dispose of loose electrons. What happens to them?
Combined with protons that have arrived from ATP synthase and Oxygen
Where does oxygen come from?
Inhalation
What does combination of electrons and oxygen and hydrogens form after the electron transfer chain?
Water
How much ATP do you get from each molecule of glucose?
Roughly 32 ATP
Most of energy is produced in which process?
Electron Transport Chain?
What process does it use?
Oxidative Phosphorylation
Are electron transport chain outcomes of ATP exact?
No, variable. But 32 is approximate. Just know it produces majority of ATP
Oxidative= Aerobic Reduction = Anaerobic
Glycolysis = Anaerobic (Oxygen not necessary for that pathway) Krebs = Aerobic - MUST HAVE OXYGEN EVEN THOUGH ITS NOT USED DIRECTLY
What role does oxygen play in Krebs cycle?
The products formed from Krebs need oxygen present to be moved away and used in electron transport chain.
Does not require O2 (creatine kinase and glycolysis) Requires O2 (Electron Transport Chain and Krebs Cycle)
Anaerobic
Aerobic
If electron transport chain (ETC) comes to a halt because of no O2, what else will stop because it is intertwined with ETC?
Krebs cycle
During heavy exercise, there is an increase in blood lactate seen.
Interpreted to mean that body was converting from aerobic to anaerobic mechanisms for ATP synthesis due to lack of oxygen in mitochondrion. Is this definition true?
NOPE!
What is produced and shifted to krebs cycle at end of glycolysis?
Pryuvate
In a healthy person, ___ is present in
mitochondrion
Oxygen
The reason for buildup of lactate is because Krebs and ETC have a collectively _______er velocity than the glycolysis enzymes
Slower
What does the slower rate of ETC and Krebs vs glycolysis cause?
What happens to the molecule?
A build up of pyruvate
It shuttles over to lactate
Lactate then diffuses out of muscle cell into bloodstream and can be used by other muscle cells (slow oxidative) and reconvert it back to pyruvate and use it
!
Can the heart use lactate? Why?
Yes. Because it has huge numbers of mitochondria
Is lactate a waste product?
No. It’s a fuel.
The physiological inability to contract skeletal muscle
Fatigue
Causes of fatigue
ATP production can’t keep up with usage
Psychological Factors
pH changes (lactate acid is acid, makes enzymes less efficient)
Neurological transmission of action potential, either through nerve or at n-m junction
Ionic Imbalance - K+ loss
Mitochondrial Function (Chronic Fatigue Syndrome)
Replenishment of oxygen reserves, glycogen stores, ATP re-synthesis
Excess postexercise O2 consumption
How efficient is skeletal muscle?
20-25%
What happens to the rest of energy? Mostly good thing unless there’s too much of it.
Lost as heat
Fuel source for ATP production
Glucose
Makes glycogen from glucose
Glycogenesis
Breakdown glycogen to extract glucose
Glycogenolysis
Make glucose from other source (ex: amino acids)
Gluconeogenesis
Also used for fuel. Products of breakdown can be fed into krebs, glycolysis pathway and energy is extracted
Lipids
Storage of lipids
Lipogenesis
Break down of fat to use for energy
Lipolysis
Can also be used for fuel, rarely a good thing because you are at starvation
Proteins
How can amino acids be used as energy?
Oxidation of amino acids
