L2;C2 Flashcards
How is energy measured in biological systems?
Energy is measured in kilocalories. All energy is eventually converted to heat.
One Kcal is the amount of heat energy needed to raise:
1kg of water by 1 degree Celsius
What are the three types of work? Provide a description of each.
Mechanical work: muscle contractions, cell division; this needs heat or energy
Chemical work: synthesis of molecules
Transport work: diffusion, active transport
What are the three components to supplying energy?
Carbs, fats, proteins
At rest, what percentage of energy does CHO and fats provide?
80-90%
What is type of energy mainly used during short intensity exercise?
CHO
What type of energy is mainly sued during long less intense exercise?
CHO, fats and 10% protein
Provide a brief description of CHO and what they get converted to, their storage component, etc.
Carbohydrates get converted to glucose and be converted to glycogen
The two storage components for glycogen are muscles and liver. Muscles being the largest component of storage.
Provide a brief description of fats and what they get converted to, their storage component, etc.
Fats are stored as triglycerides. These are made up of a glycerol molecule and three fatty acids. Most energy is derived from breaking dow fat instead of CHO.
Where is most fat located?
Visceral and subcutaneous areas
Provide a brief description of proteins and what they get converted to, their storage component, etc.
Proteins are not really stored anywhere, to be used they must lose their nitrogen group and the new processed or broken down.
How are FFA mobilized?
- when FFA is in short supply, it is replenished via triglycerides in adipose tissue
- lipase (hormone sensitive) catabolizes adipose triglyceride and transports to mitochondria
- muscle triglyceride are also metabolized to provide fatty acids
What complex is used to transport FFA?
Carnitine enzyme complex provides transport to FFA during the mobilization phase
What are coenzymes? what do they do?
These are non protein organic substances. They assist enzymes action by binding the substrate to the enzyme.
What are the type types of enzyme inhibition? Describe them.
Competitive inhibition= substrates that closely resemble the target substrate but cannot be changed by the enzyme. These bind to the enzyme activity site.
Noncompetitive inhibition= these do not resemble the targeted substrate. These bind to non active sites. They alter enzymes.
What are the two redox reactions? Wha do they do?
Oxidation= this is the loss of an electron, this then has a transfer of O2, H2, or e-
Reduction= this is a gain of electrons
What is the mass action effect?
Basically, more of a substrate. More of a product it will yield.
- chemical processes progress towards the products with additional reactants
- addition of products causes the progression towards reactants
- changing the [] of a substance alters different reactions
We derive energy from food and store it as high energy compounds of ______
ATP
CHo is stored as ______ in muscles and the liver
Glycogen
Fat is stored as triglycerides and broken into ______
FFAs
The three main systems for ATP generation
- ATP-PCr system
- Glycolytic system
- Oxidative system
Explain how the PCr system creates ATP
- PCr break into Pi and Cr
- free energy, Pi, and ADP for ma reaction
- this creates ATP
Wha enzyme causes the breakdown of PCr?
Creation kinase
What provides the demand of ATP in the PCr system?
The breakdown of PCr will explain the demand of ATP
PCr breakdown—> ATP demand—> ATP supply
What is the adenylate kinase reaction? What does it do?
- this reforms ATP using two ADP molecules. Results in ATP and AMP
- Adenylate kinase itself drives the reaction
Within metabolic reactions, what needs an doesn’t need ATP?
Glycogen doesnt need ATP since its the starting molecule of reactions, glucose does need ATP in order to convert to glycogen.
What are the steps for glycolysis (shortened) ?
- Glucose or glycogen is broken down into pyruvic acid
- without O2 present, pyruvic acid is converted to lactic acid
- oxygen isn’t an essential for anaerobic glycolysis’ final synthesis
What is the rate limiting enzyme for glycolysis?
PFK-1 this is an allosteric rate limiting enzyme
1 mole of glucose —> ____ moles of ATP
1 mole of glycogen —> ____ moles of ATP
2, 3
3 Key points for the PCr reaction:
- The separation of Cr and Pi is caused by creatine kinase
- 1 mol of ATP per 1 mole of PCr
- Pi is combined with ADP to form 1 ATP
What is aerobic glycolysis?
- this plays a role in both aerobic and anaerobic systems
- this process is the same regardless of O2 being present (minus the end product of lactic acid and pyruvate)
What are some of the steps and key points for the kreb cycle?
(Recall, every glucose molecule yields two moles of pyruvate. Meaning every glucose entered in thee system can allow for two runs of the kreb cycle)
- when succinyl CoA is converted into succinate, this results in GTP production which transfers Pi to ADP forming ATP
- ## the inhibitor of the kreb cycle is isocitrate dehydrogenase (IDH) which is inhibited by ATP and activated by ADP and Pi
Substrate level phosphorylation produces _____ molecules of ATP within kreb cycle for every glucose molecule
2
What two enzymes/molecules within the kreb cycle are used during studies tro determine aerobic metabolism?
Citrate synthase, succinyl CoA
Explain what the ETC does and some fo the characteristics of it
- there have ions coming in and out of the membrane which cause an electrical potential
- outside membranes are positive, inside membrane are negative (movement of H+)
- ATPsynthse is powered by proton motive forces
- this keeps producing ATP
Since H+ are a product of glycolysis and production of pyruvate, where do they go and how?
They are transported to the ETC via NAD and FAD
The cytochromes in the ETC have _____ ______ ______ passing to each other throughout the cycle
High energy electrons
Energy pumps ______ into and out of the matrix forming ______
Electrons ATP
What is the process at the end of the ETC that involves ATPsynthase? What does it use and produce?
Oxidative phosphorylation is at the end of ETC and involves ATP synthase which uses O2 and H2 to produce H2O. ATP
With regards to oxidation of fat, what does lipolysis do?
Lipolysis breaks triglycerides to glycerol and 3 FFAs
Explain some characteristics and steps to Beta oxidation of fats.
- FFAs are oxidized to form active FFAs, this is used for energy to start teh system up
- an abundance of Carbon and Hydrogen is needed to produce the ending product of 2 hydrogen molecules but needs lots of Oxygen to expel
- fat is stored in adipose and muscle tissue as triglycerides. These break into glycerol and FFAs
- Beta oxidation produces 28 ATP
What is the interaction or relationship between energy system with respect to maximal ATP generation?
Fastest to slowest:
PCr, glycolysis, CHO oxidation, Fat oxidation
What is the interaction or relationship between energy system with respect to maximal available energy?
Most storage to least storage:
Fat oxidation, CHO oxidation, glycolysis, PCr
Oxidation of CHO with regards to glucose produces ____ ATP
Oxidation of CHO with regards to glycogen produces ____ ATP
32, 33
Why is the reduction of ATP in glucose oxidation of CHO 32?
This is reduced due to the shuttling of electrons and energy usage
The oxidative capacity of muscle fibres depend on 4 things
Oxidative enzyme levels
Fibre type
Composition
O2 availability
The process of protein or fat converting to glucose is _________
The process of protein to fatty acids is _______
Gluconeogenesis
Lipogenesis
How do enzymes work?
They lower activation energy
