Chapter Two: Metabolism Flashcards
The sum of all chemical reactions occurring in a living organism is known as:
Metabolism
What is metabolism?
The sum of ALL chemical reactions that occur in a living organism
What is a sequence of many chemical reactions that depend on each other?
Metabolic Pathways
What is a metabolic pathway?
A sequence of many chemical reactions that all depend on each other
What is chemical thermodynamics?
The study of energy changes in chemical systems
What is the study of energy changes in chemical systems?
Chemical thermodynamics
What is bioenergetics?
The science of energy transposition under varying metabolic conditions
What is the science of energy transposition under varying metabolic conditions?
Bioenergetics
What is Gibb’s Free Energy (G)?
The energy available to do work
The energy available to do work is known as:
Gibb’s Free Energy (G)
If ΔG < 0, the reaction is said to be:
Exergonic
If ΔG > 0, a reaction is said to be:
Endergonic
If a reaction has a ΔG < 0, the reaction:
Proceeds spontaneously
If a reaction has a ΔG > 0 the reaction:
Will not proceed spontaneously
Exergonic reactions have a ΔG ___ 0.
Less than (<)
Endergonic reactions have a ΔG of ___ 0.
Greater than (>)
What is equilibrium in a chemical reaction?
When there is no net change in reactants and products
When there is no net change in the reactants and products of a reaction, it is said to be in___.
Equilibrium
If a reaction has reached equilibrium, it’s ΔG____.
=0
When ΔG = 0, a reaction has reached:
Equilibrium
Free energy is measured in what units?
Joules, kilojoules, and kilocalories
1 kilocalorie = ____ J
4,184 Joules
What is ATP composed of?
Adenine
Ribose
Phosphoryl groups
What is Pi?
What is PPi?
Inorganic phosphate
Inorganic pyrophosphate (pyrophosphate)
When ATP + H2O <===> ADP + Pi + H+, how much energy results?
What type of reaction is it?
ΔG = -7.3 kcal
Exergonic
When ATP + H2O <===> AMP + PPi + H+, how much energy is produced?
What kind of reaction is it?
ΔG = -10.9 kcal
Exergonic
When PPi + H2O <==> 2 Pi + H+, how much energy is produced?
What kind of reaction is it?
ΔG = -4.6 kcal
Exergonic
When ATP + 2 H2O <===> AMP + PPi + 2 H+, how much energy is produced?
What kind of reaction is it?
ΔG = -15.5 kcal
Exergonic
What is catabolism?
A degradation process where biological molecules are broken down into smaller molecules
When biological molecules are broken down into smaller molecules, this is known as:
Catabolism
What is anabolism?
A biosynthetic process where larger molecules are formed from smaller units (metabolites)
When larger molecules are formed from smaller molecules, this is known as ____.
Anabolism
Catabolism _____ energy, and anabolism ____ energy.
Releases, requires
Because anabolism requires energy, it must be coupled with an:
Exergonic reaction
What is the central concept of metabolism?
Catabolism yields energy for synthesis of ATP, which is spent in biological functions requiring energy (anabolism, work)
What is oxidation?
A loss of electrons
What is it called when something loses electrons?
Oxidation
What is reduction?
When something gains electrons
When something gains electrons this is known as:
Reduction
If a molecule is oxidized, another MUST be ___.
Reduced
If a molecule is reduced, another MUST be___.
Oxidized
What is a redox reaction?
When one molecule is oxidized, and another is reduced
Metabolites are oxidized by electron removal in ____.
Catabolism
Metabolites are reduced by electron addition in ____.
Anabolism
What is the full name of NAD+?
Nicotinamide Adenine Dinucleotide
What is NAD+?
An important electron carrier, necessary for catabolism
What is the full name of NADP+?
Nicotinamide Adenine Dinucleotide Phosphate
What does NADPH do?
It is the main electron donor in reduction reactions for anabolism
What is the full name of FAD?
Where is it derived from?
Flavin Adenine Dinucleotide
Derived from riboflavin (Vitamin B2)
Is FAD an oxidant or a reductant?
Oxidant
The ultimate electron receptor (oxidant) in metabolism is?
O2
What are the stages of catabolism?
Stage 1: Gut
Stage 2: Inside Cells
Stage 3: Mitochondria
What happens in stage 1 of catabolism?
Macromolecules are broken down in the gut into their monomers
Carbohydrates break down into:
Glucose
Lipids break down into:
Fatty acids, glycerol
Proteins break down into:
Amino acids
How much ATP is synthesized in stage 1 of catabolism?
Zero
What happens in stage 2 of catabolism?
Metabolites are further degraded into compounds central to metabolism
Glucose and glycerol are ____ in glycolysis?
Oxidized
Glycolysis breaks a glucose molecule into:
Two pyruvate molecules
Each pyruvate molecule is broken down into:
What is also released?
Acetyl-CoA
CO2
Fatty Acids are ____ in β-oxidation.
Oxidized
Fatty acids, glucose, and glycerol enter the common pathways as____.
Acetyl-CoA
Amino acids follow individual pathways and enter common pathways at:
Numerous points
How much ATP is produced in Stage 2 of catabolism?
A small amount
(Usually 4 ATP)
Where does stage 3 of catabolism occur?
In the mitochondria
The citric acid cycle is also known as:
Krebs Cycle
TCA cycle -Tricarboxylic Acid Cycle
Electrons are initially passed to ____ and ____ before passing to _____.
NAD+, FAD
O2
Where does the electron transport chain occur?
In the inner membrane of the mitochondria (matrix)
What is stage 3 of catabolism?
Mitochondria
Acetyl-CoA is oxidized in the:
Citric Acid Cycle
Energy from the Exergonic oxidations is used to generate most of the cells ATP in a process known as:
Oxidative Phosphorylation
What is phosphorylation?
The addition of a phosphoryl (phosphate) group to a compound
The addition of a phosphoryl (phosphate) group to a compound is known as:
Phosphorylation
Once carbon has been completely oxidized it is expelled as:
CO2
