High-Energy Molecules And Metabolism Flashcards
mod 3 pg. 14-16 (45 cards)
What are the two main types of reactions involved in metabolism?
Anabolic and catabolic reactions
Anabolism builds larger molecules from smaller ones, while catabolism breaks down macromolecules to release energy.
What is the role of anabolism in metabolism?
Consumes ATP to build larger molecules
Example: gluconeogenesis.
What is the role of catabolism in metabolism?
Breaks down macromolecules and releases energy stored in ATP
Example: glycolysis.
Which four tissues coordinate energy metabolism?
Liver, adipose, skeletal muscle, brain
These tissues specialize in storage, use, or generation of specialized fuels.
How do tissues communicate in energy metabolism?
Via nervous system, substrate availability, plasma hormone concentration
This communication is crucial for coordinating energy needs.
What is the function of insulin in energy metabolism?
Anabolic hormone promoting synthesis and energy storage
Released after meals when energy levels are high.
What is the function of glucagon in energy metabolism?
Catabolic hormone to stimulate catabolic pathways
Released when energy levels are low to maintain normal blood glucose.
What are catecholamine hormones and when are they secreted?
E.g. epinephrine & norepinephrine; secreted in response to neural signals
They play a role in the body’s response to stress.
What is ATP and its role?
Primary energy source for many cellular processes
Composed of adenosine sugar, ribose, and 3 phosphate groups.
What is GTP and its role?
Used in specific energy reactions like protein synthesis and gluconeogenesis
Composed of guanosine sugar, ribose, and 3 phosphate groups.
What is the standard free energy change (ΔG°) associated with ATP?
Energy between 2nd & 3rd phosphates of ATP = -7.3 kcal/mol
Indicates the amount of energy released when ATP is hydrolyzed.
What happens when the 3rd phosphate of ATP is removed?
ADP is formed and energy is released
This process is crucial for cellular energy transfer.
What is energy coupling?
Endergonic reaction (requires energy) with an exergonic reaction (releases energy) share a common intermediate to make the overall process favorable.
Example: Hydrolysis of ATP coupled with protein synthesis.
How does ATP function as an allosteric factor?
Binds to enzymes outside the active site, changing the enzyme’s shape
This can activate or inhibit enzyme activity.
What high-energy form does FAD produce?
FADH2
Produced by adding 2 H+’s to FAD.
What high-energy form does NAD+ produce?
NADH
Produced by adding H+ and 2e- to NAD+.
What is the role of NADP+ in metabolism?
Used in anabolic processes like gluconeogenesis and lipid synthesis
It differs from NADH by having an additional phosphate group.
What happens to NADP and GDP in low energy conditions?
Converted to NADPH and GTP
These conversions support special processes that need to run when energy is low.
What is the daily energy requirement for an adult in kcal?
2000 kcal/day
This equates to approximately 83 kg of ATP.
How much ATP does the body have at any given time?
250 g of ATP
This ATP is recycled over 300 times a day.
Where does the majority of ATP regeneration occur?
In the mitochondria through oxidative phosphorylation.
What are the primary sources of ATP?
- Carbohydrates
- Triglycerides and lipids
- Amino acids from proteins
What is the structure of the inner membrane of mitochondria?
Increased surface area and forms cristae. Impermeable.
What is the function of the inner membrane in mitochondria?
Crucial for forming chemiosmotic proton gradient.
