Which of the following is NOT required for gluconeogenesis from lactate?

Transamination of pyruvate to alanine

Transport of lactate from muscle to liver

Conversion of lactate to pyruvate

Which of the following statements about gluconeogenesis is correct?

It uses exactly the same enzymes as glycolysis in reverse

It only occurs during fed state when insulin levels are high

Fatty acids are the primary substrate for gluconeogenesis

In type I diabetes, which of the following is the MOST characteristic metabolic change that distinguishes it from type II diabetes:-

Increased hepatic glucose output

A medical student consumes a meal containing 60g carbohydrates, 20g protein, and 15g fat after an 8-hour fast. Which one of the following is the MOST prominent effect of this meal on the student's metabolic state?

Liver glycogen stores will be replenished.

The rate at which fatty acids are converted to adipose triacylglycerols will be increased.

Blood glucagon levels will decrease.

The rate of gluconeogenesis will be increased.

Which of the following is FALSE about insulin action?

Insulin promotes glycogen synthesis

In a patient who has been in a state of starvation for 72 hours, which of the following is the primary mechanism for maintaining blood glucose levels?

Increased ketosis due to breakdown of fats

Which of the following is not an effect of insulin?

Increased transport of glucose into cells

Induction of lipoprotein lipase

Fed State Metabolism for NEET-PG: High-Yield Biochemistry Lessons

Fed State: Introduction - Fuel Flood Fiesta

Aka: Absorptive / Post-prandial state.
Timing: Begins after nutrient ingestion; lasts 2-4 hours.
Hallmark: "Fuel Flood" - influx of glucose, amino acids, fats (chylomicrons).
Primary Driver: ↑ Insulin secretion (pancreatic β-cells).
- Responds to ↑ blood glucose & amino acids.
Hormonal Milieu:
- ↑ Insulin : Glucagon ratio.
- ↓ Glucagon, ↓ Epinephrine, ↓ Cortisol.
Overall Goal: Anabolism - utilize & store incoming nutrients.
- Energy needs met by absorbed glucose.
- Excess nutrients stored: Glycogen, Triacylglycerols (TAGs), Proteins.

⭐ Insulin is the major anabolic hormone of the fed state, promoting synthesis and storage of nutrients.

Fed State: Carbohydrates - Sugar Stash & Burn

Stimulus: ↑ Post-meal blood glucose.
Key Hormone: Insulin.
Effects: Glucose uptake, glycogenesis, glycolysis, lipogenesis.
Liver (GLUT2; pathways insulin-stimulated):
- ↑ Glycogenesis (storage).
- ↑ Glycolysis (ATP, Acetyl-CoA for FA synthesis).
- ↑ PPP (NADPH for FA synthesis).
- ↑ FA synthesis, VLDL export.
Muscle (GLUT4, insulin-dependent):
- ↑ Glucose uptake.
- ↑ Glycogenesis (storage).
- ↑ Glycolysis (ATP).
Adipose (GLUT4, insulin-dependent):
- ↑ Glucose uptake.
- ↑ Glycolysis (Glycerol-3P for TGs).
- ↑ TG storage.
Brain (GLUT1/3), RBCs (GLUT1): Insulin-independent glucose use. RBCs: anaerobic glycolysis.

⭐ GLUT4, found in muscle and adipose tissue, is the insulin-responsive glucose transporter crucial for postprandial glucose uptake.

📌 GLUTs: 1(RBC/Brain), 2(Liver/Pancreas), 4(Muscle/Adipose, Insulin ↑).

Glucose Metabolism in the Fed State

Fed State: Lipids & Proteins - Fat Packing & Building

Lipid Metabolism (Storage Dominates):
- Dietary Fats (Chylomicrons, CM):
  - CMs transport dietary TGs.
  - Insulin & Apo C-II activate Lipoprotein Lipase (LPL).
  - LPL: TGs (CM/VLDL) → FAs + Glycerol. FAs enter adipose/muscle.
- Liver-derived Fats (VLDL):
  - Excess calories → De Novo Lipogenesis (liver) → TGs → VLDL.
- Adipose Tissue (Insulin's Role):
  - ↑ GLUT4 uptake, ↑ Glycolysis (Glycerol-3-P for TG synthesis).
  - ↑ LPL activity (FA uptake), ↓ Hormone-Sensitive Lipase (HSL) activity (prevents lipolysis).
Protein Metabolism (Synthesis Focus):
- Amino Acids (AAs):
  - Liver: Synthesizes plasma proteins (e.g., albumin), non-essential AAs. Excess AAs → energy/fat precursors; N → urea.
  - Peripheral Tissues: Insulin ↑ AA uptake & protein synthesis (muscle).

⭐ Insulin promotes TG storage by activating LPL (FA uptake from CM/VLDL) & inhibiting HSL (prevents fat breakdown) in adipose tissue during fed state.

Fed State: Organ Integration - Metabolic Symphony

High insulin:glucagon ratio orchestrates metabolic harmony post-meal.

Organ	Fed State Role (Insulin ↑)
Liver	Glucose → Glycogen; Excess Glucose/AA → FAs → TGs (VLDL); Protein synthesis.
Muscle	Glucose uptake (GLUT4) → Glycogen, ATP; Protein synthesis.
Adipose	Glucose uptake (GLUT4) → Glycerol-3P; FAs (Chylomicrons, VLDL via LPL) → TGs (storage).
Brain	Glucose uptake (GLUT1/3); Primary fuel.
RBCs	Glucose uptake (GLUT1); Anaerobic glycolysis ($2$ ATP/glucose).

High‑Yield Points - ⚡ Biggest Takeaways

Insulin is the dominant hormone; glucagon is suppressed.

Glucose is the primary fuel for most tissues.

Liver: ↑ glycogenesis, ↑ lipogenesis from excess glucose, ↑ protein synthesis.

Adipose tissue: ↑ glucose uptake (GLUT4), ↑ triglyceride synthesis & storage; LPL active.

Muscle: ↑ glucose uptake (GLUT4), ↑ glycogen synthesis, ↑ protein synthesis.

Brain utilizes glucose (insulin-independent uptake).

RBCs rely on anaerobic glycolysis of glucose.

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