Lecture 22: Energy balances in cells/organisms Flashcards
What is the first law of thermodynamics and how does it relate to the human body?
- The total energy within a system is constant
- Energy cannot be created or destroyed
- Energy can be converted between forms
The body can’t create or destroy energy—only change it. It can be stored in chemical bonds and be used for vital life processes
Biochemistry relies on ________ conversions.
energy conversions
What is anabolism?
Anabolism (A: adding) Energy used to make bigger molecules (fuel molecules)
What is catabolism?
Catabolism (C: cutting)/ Respiration Energy released when large molecules broken down
Why is ATP suited to act as the energy currency in our cells?
(high energy phosphate bonds - quick release)
ATP is ideal as the cell’s energy currency because it stores energy in its high-energy phosphate bonds, which can be quickly released for cellular activities when needed.
What are the four macronutrients in the diet and what subunits (monomers) are they composed of?
Carbohydrate - Monosaccharides (glucose)
Fat - Fatty acids
Protein - Amino acids
Nucleic Acids - Nucleotides
What are the important inorganic molecules in the diet?
Major/macro and minor/trace minerals
What are the major minerals found in the human body?
Major minerals: High abundance
CPMSPC (Coffee Powered Mornings Save People’s Careers)
Calcium (Ca)
Phosphorus (P)
Magnesium (Mg)
Sodium (Na)
Potassium (K)
Chlorine (Cl)
What are the minor minerals found in the human body?
Minor minerals: (low concentrations)
Iron (Fe)
Zinc (Zn)
Selenium (Se)
Iodine (I)
Copper (Cu)
Chromium (Cr)
Manganese (Mn)
Molybdenum (Mo)
What two categories are vitamins spilt into? And can these respective classes be stored?
water soluble - not stored; B class in metabolism
fat soluble - can be stored
What is the role of a cofactor?
Minerals and vitamins are often cofactors:
- small molecules required for the activity of an associated
enzyme
- range of mechanisms
What are the three key properties of coenzymes in relation to the metabolic pathways?
Coenzyme
- type of cofactor
- organic, often derived from vitamins
Key features of coenzymes in the pathways:
- low concentration in cells
- act as carriers (transfer things)
- have two forms
If a reaction has a negative ΔG, is it spontaneous or nonspontaneous?
Spontaneous
What key type(s) of reaction happens to fuel molecules in the pathways?
Two key reaction types:
1. Those involving ADP and ATP
2. Redox reactions:
- fuel molecules get oxidized
What is meant be the term “reducing equivalent”?
Biological redox reactions often involve the transfer
of hydrogen (H) atoms (includes an e-)
Hydrogen referred to as a reducing equivalent
