Lipid and Amino Acid Metabolism Overview

Triglycerides

Hydrolyzed to glycerol and fatty acids during digestion.

Phosphoglycerides

Hydrolyzed to component substances in lipid metabolism.

Chylomicrons

Lipoprotein aggregates for lipid transport in blood.

Lipoproteins

Complexes of lipids and proteins, classified by density.

VLDL

Very low density lipoprotein, rich in triglycerides.

LDL

Low density lipoprotein, associated with cholesterol transport.

HDL

High density lipoprotein, involved in cholesterol removal.

Fat Mobilization

Hydrolysis of triglycerides for energy production.

Glycerol

Converted to dihydroxyacetone phosphate for glycolysis.

Fatty Acids

Mobilized for energy when glycogen stores are low.

Serum Albumin

Plasma protein that transports fatty acids in blood.

ATP Hydrolysis

Provides energy for fatty acid activation to acyl CoA.

Acyl CoA Synthetase

Enzyme that catalyzes fatty acid activation.

β-Oxidation

Pathway for fatty acid catabolism to acetyl CoA.

Ketone Bodies

Produced during fat metabolism under low carbohydrate conditions.

Urea Cycle

Pathway for amino acid nitrogen disposal as urea.

Transamination

Reaction transferring amino group to form new amino acid.

Deamination

Removal of amino group from amino acids.

Amino Acid Pool

Source of amino acids for protein synthesis and metabolism.

Gluconeogenesis

Synthesis of glucose from non-carbohydrate sources.

Energy Production

Amino acids can be used for cellular energy.

Triglyceride Resynthesis

Occurs in intestinal mucosa after lipid digestion.

Blood Lipid Behavior

Increases after meals, normalizes through storage and oxidation.

Lipid Digestion

Triglycerides hydrolyzed to glycerol and fatty acids.

Chylomicrons

Lipoprotein aggregates transporting insoluble lipids.

Fat Mobilization

Hydrolysis of triglycerides for energy use.

Glycerol Metabolism

Converted to dihydroxyacetone phosphate in glycolysis.

Fatty Acyl CoA

Activated form of fatty acids for catabolism.

Acyl CoA Synthetase

Enzyme catalyzing fatty acyl CoA formation.

ATP Hydrolysis

Energy source for fatty acid activation.

β-Oxidation

Process of fatty acid catabolism for energy.

Ketone Bodies

Produced during fat metabolism under specific conditions.

Urea Cycle

Pathway converting ammonia to urea for excretion.

Transamination

Amino group transfer between amino acids and keto acids.

Energy Production

Amino acids can generate ATP through various pathways.

Triglyceride Resynthesis

Reformation of triglycerides in intestinal mucosa cells.

Blood Lipid Behavior

Lipids increase post-meal, normalize through storage.

Lipoprotein Classification

Based on density; higher lipids, lower density.

VLDL

Very low density lipoprotein, transports triglycerides.

LDL

Low density lipoprotein, carries cholesterol to cells.

HDL

High density lipoprotein, removes cholesterol from cells.

Amino Acid Pool

Body's reservoir of amino acids for metabolism.

Nonessential Amino Acids

Synthesized from carbohydrate metabolism intermediates.

Fatty Acid Transport

Fatty acids bind to serum albumin in blood.

Fatty acyl-CoA

A substrate for subsequent Ⱦ-oxidation cycles.

Ⱦ-oxidation

Metabolic process for fatty acid degradation.

Substrate

A reactant in a biochemical reaction.

Final step

Last phase before the substrate is reused.

Next round

Subsequent cycle of metabolic processing.

β-oxidation

Process of fatty acid degradation in mitochondria.

Acetyl-CoA

Two-carbon molecule produced from fatty acid oxidation.

Fatty Acid Spiral

Pathway for sequential degradation of fatty acids.

NADH

Electron carrier producing 2.5 ATP per molecule.

FADH2

Electron carrier producing 1.5 ATP per molecule.

Stearoyl CoA

Activated form of stearic acid for oxidation.

Activation Step

Initial reaction using ATP to activate fatty acids.

Citric Acid Cycle

Pathway where acetyl CoA enters for energy production.

Energy Density

Fatty acids provide more energy than carbohydrates.

Ketonemia

Elevated ketone bodies in blood over 20 mg/100 mL.

Ketonuria

Presence of ketone bodies in urine.

Acetone Breath

Detection of acetone in breath indicating ketosis.

Ketosis

Condition with ketonemia, ketonuria, and acetone breath.

Ketoacidosis

Low blood pH due to high ketone levels.

Insulin Treatment

Used to manage diabetes-related ketosis.

Sodium Bicarbonate

Used to restore acid-base balance in severe ketosis.

ATP Calculation

Determining ATP yield from fatty acid oxidation.

Citrate Transport

Process of moving acetyl CoA to cytoplasm.

Oxaloacetate

Intermediate for transporting acetyl CoA to cytoplasm.

Butyryl CoA

Four-carbon chain entering the β-oxidation sequence.

Total ATP from Stearic Acid

120 ATP produced from complete oxidation.

Energy Comparison

Lipids are 25% more efficient than carbohydrates.

Hydrolysis of ATP

Releases energy for fatty acid activation.

Fatty Acid Synthesis

Opposing process of fatty acid degradation in cytoplasm.

Fatty Acyl-CoA

Activated fatty acid ready for β-oxidation.

NADH

Electron carrier produced during β-oxidation.

FADH2

Another electron carrier generated in β-oxidation.

Fatty Acid Spiral

Cyclic pathway for fatty acid degradation.

Activation Step

Initial reaction forming fatty acyl-CoA from fatty acid.

Stearoyl-CoA

Fatty acyl-CoA derived from stearic acid (C18).

Energy Yield

Total ATP produced from stearic acid oxidation.

Citric Acid Cycle

Pathway where acetyl-CoA enters for further energy production.

ATP Production

10 ATP per acetyl-CoA in citric acid cycle.

Ketonemia

Elevated ketone bodies in blood (over 20 mg/100 mL).

Insulin Treatment

Restores glucose metabolism, reduces ketone formation.

Sodium Bicarbonate

Used to treat dehydration and acid-base imbalance.

Fatty Acid Synthesis

Opposing process to fatty acid degradation in cytoplasm.

Citrate Transport

Mechanism transporting acetyl-CoA to cytoplasm.

Oxaloacetate

Molecule that combines with acetyl-CoA for transport.

Butyryl-CoA

Four-carbon fatty acyl-CoA in final β-oxidation step.

Energy Density

Lipids contain more energy than carbohydrates.

ATP Multipliers

Conversions: 10 ATP per acetyl-CoA, 2.5 per NADH, 1.5 per FADH2.

Malonyl-ACP

Carries carbon atoms in fatty acid synthesis.

Fatty Acid Synthetase System

Multienzyme complex catalyzing fatty acid synthesis.

Acyl Carrier Protein (ACP)

Protein that holds growing fatty acyl chain.

Triglycerides

Stored form of fat in adipose tissues.

Adipose Tissue

Body tissue that stores fat as triglycerides.

Polyunsaturated Fatty Acids

Cannot be synthesized by the human body.

Linoleic Acid

Dietary fatty acid converted to other polyunsaturates.

Linolenic Acid

Dietary fatty acid also converted to polyunsaturates.

Glucose to Fatty Acids

Human body can convert glucose into fatty acids.