Biochemistry Flashcards
Biochemical Reactions and other such nonsense.
Why is glucose considered the body’s primary energy source?
Glucose is the primary energy source because:
- It’s readily available from carbohydrate digestion
- It can be quickly metabolized for energy
- All cells can use it
- It can be stored as glycogen for later use
- It’s essential for brain function
How does the availability of glucose contribute to its role as a primary energy source?
Glucose is readily available from carbohydrate digestion, making it a convenient and accessible energy source for the body.
What advantage does glucose have in terms of metabolism speed?
Glucose can be quickly metabolized for energy, allowing cells to rapidly access the energy they need.
How does glucose’s versatility contribute to its importance as an energy source?
All cells in the body can use glucose as an energy source, making it a universal fuel for cellular processes.
What storage form does glucose take in the body, and why is this important?
Glucose can be stored as glycogen in the liver and muscles for later use, providing an energy reserve when glucose is not immediately available from the diet.
Why is glucose particularly important for brain function?
Glucose is essential for brain function because the brain primarily relies on glucose for energy and cannot efficiently use other fuel sources.
Where do the main bioenergetic reactions occur in the cell?
- Cytoplasm: Glycolysis
- Mitochondrial matrix: Krebs cycle, fatty acid oxidation
- Inner mitochondrial membrane: Electron transport chain, oxidative phosphorylation
- Endoplasmic reticulum: Lipid synthesis
- Peroxisomes: Fatty acid oxidation (very long-chain fatty acids)
What bioenergetic process occurs in the cytoplasm?
Glycolysis occurs in the cytoplasm.
Which bioenergetic reactions take place in the mitochondrial matrix?
The Krebs cycle and fatty acid oxidation occur in the mitochondrial matrix.
What processes are associated with the inner mitochondrial membrane?
The electron transport chain and oxidative phosphorylation are associated with the inner mitochondrial membrane.
Where does lipid synthesis primarily occur in the cell?
Lipid synthesis primarily occurs in the endoplasmic reticulum.
What specific type of fatty acid oxidation occurs in peroxisomes?
Peroxisomes are responsible for the oxidation of very long-chain fatty acids.
Define aerobic metabolism and provide a bioenergetic example.
Aerobic metabolism: Requires oxygen for complete oxidation of substrates
* Example: Complete glucose oxidation through glycolysis, Krebs cycle, and electron transport chain.
Define anaerobic metabolism and provide a bioenergetic example.
Anaerobic metabolism: Occurs without oxygen
* Example: Lactic acid fermentation during intense exercise
How does the presence or absence of oxygen differentiate between aerobic and anaerobic metabolism?
Aerobic metabolism requires oxygen for complete oxidation of substrates, while anaerobic metabolism occurs without oxygen.
What is an example of a complete aerobic metabolic pathway?
A complete aerobic metabolic pathway is the oxidation of glucose through glycolysis, the Krebs cycle, and the electron transport chain.
In what physiological situation might anaerobic metabolism, such as lactic acid fermentation, occur?
Anaerobic metabolism, like lactic acid fermentation, occurs during intense exercise when oxygen supply is insufficient to meet the energy demands of the muscles.
What are the major steps and products of glycolysis?
Major steps:
- Glucose → 2 Pyruvate
- Products:
- Net production: 2 ATP, 2 NADH
Describe the major steps and products of the Krebs cycle.
Major steps:
- Acetyl-CoA → 2 CO2
- Products per cycle:
- 3 NADH, 1 FADH2, 1 GTP
What are the key components involved in the Electron Transport Chain (ETC)?
- Key components:
- NADH and FADH2 (electron carriers)
List the key enzymes involved in glycogen metabolism and their functions.
- Glycogen synthase: Adds glucose units to glycogen
- Glycogen phosphorylase: Breaks down glycogen to glucose-1-phosphate
- Branching enzyme: Creates branch points in glycogen
- Debranching enzyme: Removes branch points during glycogen breakdown
Describe the steps of glycogenesis.
- Glycogenesis steps:
Glucose → Glucose-6-phosphate → Glucose-1-phosphate → UDP-glucose → Glycogen
Outline the steps of glycogenolysis.
- Glycogenolysis steps:
Glycogen → Glucose-1-phosphate → Glucose-6-phosphate → Glucose (in liver) or pyruvate (in muscle)
Provide five clinical examples of metabolism disorders.
- Diabetes mellitus: Impaired glucose metabolism
- Phenylketonuria: Phenylalanine metabolism disorder
- Glycogen storage diseases: Impaired glycogen metabolism
- Fatty acid oxidation disorders: e.g., Medium-chain acyl-CoA dehydrogenase deficiency
- Urea cycle disorders: e.g., Ornithine transcarbamylase deficiency
