Exam 2: Chapter 9, Energy Metabolism Flashcards
Pathways that build compounds
anabolic
pathways that break down compounds
catabolic
What is the difference between metabolism, catabolism, and anabolism?
Metabolism can be described as a summation of both anabolism and catabolism.
- Metabolic Pathway
- A group of biochemical reactions that occur in progression from beginning to end
- Adenosine triphosphate (ATP): Body’s source of…
- Adenosine diphosphate (ADP): What results from…
- Adenosine monophosphate (AMP): Results from hydrolysis…
- Body’s source of energy derived from catabolic reactions of macronutrients
- What results from cells’ breakdown of a high phosphate bond in ATP
- Results from hydrolysis of ADP when ATP levels in cell are low
Stages of Catabolism
Structure of ATP
ATP synthesis depends on transfer of electrons in a series of reactions from energy-yielding compounds to oxygen
- Oxidation-reduction reactions occur together
- Oxidized substance:
- Reduced substance:
- Role of coenzymes NAD+ and FAD+
Oxidized substance: Loses electron(s); gains oxygen/loses hydrogen
Reduced substance: Gains electron(s); loses oxygen/gains hydrogen
Oxidizes food molecules to obtain energy
Cellular respiration
Net gain 30-32 ATP
Aerobic respiration of one glucose molecule
Net gain 2 ATP
Anaerobic respiration of one glucose molecule
Steps of Aerobic cellular respiration of glucose:
1.Glycolysis: Glucose is…
2.Transition reaction: Pyruvate is…
3.Citric Acid Cycle (CAC): Acetyl-CoA enters…
4.Electron Transport Chain: NADH+, H+, FADH2 are…
- Glycolysis: Glucose is oxidized to pyruvate, producing NADH +H+
- Transition Reaction: Pyruvate is oxidized and joined with CoA, producing acetyl-CoA and NADH +H+
- Citric Acid Cycle (CAC): Acetyl-CoA enters cycle producing NADH +H+, FADH2 and ATP; CO2 also produced
- Electron Transport Chain: NADH + H+, FADH2 are oxidized to NAD+ and FAD
Electron Transport Chain:
- Passage of electrons along a series of electron carriers
- Process called ; how energy is derived from NADH + H+ and FADH2
- Minerals involved:
- oxidative phosphorylation
- Copper: component of an enzyme
- Iron: component of cytochromes
Anaerobic Metabolism:
- Occurs in cells with no mitochondria or in all cells when there is no oxygen
- *
- Pyruvate is converted to lactate
- Lactate is picked up by the liver
- Liver synthesizes compounds used in aerobic metabolism from lactate
ATP production from fats:
Lipolysis
- Tryglycerides broken down into
Triglycerides broken down into fatty acids and glycerol
ATP production from fats:
Fatty Acid Oxidation (beta-oxidation):
- takes place in the
- shuttles fatty acids from cytosol into mitochondria
- Promoted by , , and
- Yields , and , resulting in about ATP
- Takes place in mitochondria
- Carnitine shuttles fatty acids from cytosol into mitochondria
- Promoted by glucagon, growth hormone, epinephrine
- Yields acetyl-CoA and NADH + H+ resulting in about 106 ATP
Where does ATP production of fats occur?
Alternate Fat Metabolism: Ketogenesis
- Carbohydrates aid fat metabolism
- Ketogenesis:
- Ketosis:
- Ketogenesis: Ketone bodies formed by incomplete fatty acid oxidation
-
Ketosis:
- in Type 1 Diabetes
- in Semistarvation or Fasting
Protein metabolism:
- Deamination
- Loss of:
- Requires:
- Carbon skeleton:
- Loss of the amino group from and amino acid
- Requires Vitamin B-6
- Carbon skeleton is left to enter CAC
Protein metabolism:
- Glucogenic Amino Acids
- Can form:
Can form pyruvate and become glucose
Protein metabolism:
- Ketogenic Amino Acids
- Forms…
Forms acetyl CoA and cannot become glucose
Protein Metabolism:
- Gluconeogenesis
- Forming glucose from…
- Typical fatty acids cannot…
- Forming glucose from glucogenic amino acids (e.g. alanine) and other compounds
- Typical fatty acids cannot be converted to glucose, although glycerol can
Protein Metabolism:
- Disposal of Excess Amino Groups:
- Converted to…
- Urea exreted…
- Converted to ammonia; then urea cycle
- Urea excreted in the urine
Alcohol Metabolism:
- ADH Pathway
- where does it occur?
- alcohol converted…
- acetaldehyde converted to…
- 10-30% in stomach and the rest in liver
- Alcohol converted to acetaldehyde
- Acetaldehyde converted to acetyl-CoA, producing NADH + H+
Alcohol Metabolism:
- MEOS:
- moderate to…
- uses…
- Moderate to excessive alcohol
- Uses energy rather than producing energy
Regulation of energy metabolism:
1.
2.
3.
-
Liver
- Nutrient interconversions and storage
-
ATP Concentrations regulate metabolism
- High ATP promote anabolic reactions
- High ADP stimulate catabolic reactions
- Enzymes, Hormones, Vitamins and Minerals
What happens where:
Glycolysis (glucose → pyruvate)
cytosol
What happens where:
Transition reaction (pyruvate → acetyl-CoA)
mitochondria
What happens where:
Citric acid cycle (acetyl-CoA → CO2)
Mitochondria
What happens where:
Gluconeogenesis
Begins in the mitochondria, then moves to the cytosol
What happens where:
Beta oxidation (fatty acid → acetyl-coA)
Mitochondria
What happens where:
Glucogenic amino acid oxidation (amino acids → pyruvate)
Cytosol
What happens where:
Non-glucogenic amino acid oxidation (amino acids → acetyl-CoA)
Mitochondria
What happens where:
Alcohol oxidation (ethanol → acetylaldehyde) (acetylaldehyde → acetyl-CoA)
cytosol
mitochondria
Just kinda know this chart…
Fasting encourages:
- Glycogen breakdown
- Body fat and protein breakdown
- Gluconeogenesis
- Ketogenesis
- Urea synthesis
Feasting encourages:
- Glycogen synthesis
- Body fat synthesis (lipogenesis)
- Protein synthesis
Inborn errors of metabolism
- Newborn screening
- Phenylketonuria (PKU)
- Unable to metabolize phenylalanine
- Galactosemia
- Unable to metabolize galactose
- Glycogen Storage Disease
- Inability to convert glycogen to glucose
