Food Biochemistry: Lipids Metabolism

The two primary processes involved in lipid metabolism are lipogenesis (synthesis of fats) and lipolysis (breakdown of fats).

Lipids, particularly phospholipids, are essential components of cell membranes. They form the structural basis of the membrane, creating a barrier that controls the passage of molecules in and out of the cell.

In animals, the liver is the primary site for lipid synthesis.

<p>Animals primarily obtain lipids from the food they consume.</p> Signup and view all the answers

<p>Breaking down lipids provides energy for cellular processes, especially when glucose levels are low.</p> Signup and view all the answers

<p>Lipogenesis is the process of synthesizing fats from simpler molecules like glucose. It involves the conversion of carbohydrates and proteins into fatty acids and glycerol, which are then assembled into triglycerides.</p> Signup and view all the answers

<p>Lipid metabolism is vital for maintaining energy balance, providing structural components for cells, and supporting various physiological processes. Dysregulation of lipid metabolism can lead to conditions like obesity, cardiovascular disease, and diabetes.</p> Signup and view all the answers

<p>Functional lipids besides those involved in cell membranes include hormones like testosterone and estrogen, and signaling molecules like prostaglandins, which play roles in inflammation, blood clotting, and other physiological processes.</p> Signup and view all the answers

<p>Triglycerides and cholesterol.</p> Signup and view all the answers

<p>Consumed dietary fats and stored fat.</p> Signup and view all the answers

<p>Because lipids are hydrophobic molecules.</p> Signup and view all the answers

<p>Hydrolysis.</p> Signup and view all the answers

<p>Epithelial cells of the intestinal wall.</p> Signup and view all the answers

<p>Lipid digestion and lipid catabolism.</p> Signup and view all the answers

<p>It facilitates the distribution of lipids to various tissues.</p> Signup and view all the answers

<p>The processes differ in specific mechanisms and enzymes used.</p> Signup and view all the answers

<p>Mitochondria and peroxisomes are primarily involved in lipid catabolism.</p> Signup and view all the answers

<p>Lingual lipase initiates lipid digestion in the mouth.</p> Signup and view all the answers

<p>The majority of lipid digestion and absorption occurs in the small intestine.</p> Signup and view all the answers

<p>Pancreatic lipase is responsible for hydrolyzing triglycerides into free fatty acids and glycerol.</p> Signup and view all the answers

<p>Ingested cholesterol remains intact and is not broken down by lipases.</p> Signup and view all the answers

<p>Gastric lipase and mechanical digestion through peristalsis continue fat digestion in the stomach.</p> Signup and view all the answers

<p>Chemicals from the pancreatic lipase family and bile salt-dependent lipase assist in lipid breakdown.</p> Signup and view all the answers

<p>Triglyceride digestion results in the formation of individual fatty acid units and glycerol.</p> Signup and view all the answers

<p>Small intestine</p> Signup and view all the answers

<p>Micelles</p> Signup and view all the answers

<p>Recombination of fatty acids and monoglycerides into triglycerides</p> Signup and view all the answers

<p>Chylomicrons</p> Signup and view all the answers

<p>Due to their hydrophobic nature</p> Signup and view all the answers

<p>Amphipathic structures that allow triglycerides and cholesterol to be transported through the blood</p> Signup and view all the answers

<p>Transporting digested lipids from small intestine to the rest of the body</p> Signup and view all the answers

<p>Adipose and other tissues</p> Signup and view all the answers

<p>Lipoprotein lipase breaks down triglycerides within chylomicrons and other lipoproteins into fatty acids and glycerol. This enzyme is located on the luminal surface of endothelial cells in capillaries.</p> Signup and view all the answers

<p>Glycerol is converted into glyceraldehyde 3-phosphate, an intermediate in glycolysis. This process takes place in the cytosol of the cell.</p> Signup and view all the answers

<p>Long-chain fatty acids need to be converted into fatty acyl-CoA to be able to cross the mitochondrial membrane, where beta-oxidation occurs. This conversion happens in the cytoplasm of the cell.</p> Signup and view all the answers

<p>Acyl-CoA synthetase uses energy from ATP hydrolysis to add coenzyme A to fatty acids, forming fatty acyl-CoA. This process initiates fatty acid catabolism.</p> Signup and view all the answers

<p>Beta-oxidation is a series of enzymatic reactions that break down fatty acyl-CoA molecules into acetyl-CoA units. It occurs within the mitochondria. Beta-oxidation is essential for generating energy from fatty acids.</p> Signup and view all the answers

<p>Glycerol is converted into glyceraldehyde 3-phosphate, which enters the glycolysis pathway to generate ATP. Fatty acids undergo beta-oxidation, producing acetyl-CoA, which enters the citric acid cycle and oxidative phosphorylation to produce more ATP.</p> Signup and view all the answers

<p>Lipids can provide more energy per gram than carbohydrates, making them an efficient energy store. The body can store large amounts of lipids, providing a long-term energy reserve.</p> Signup and view all the answers

<p>Lipid catabolism breaks down triglycerides into fatty acids and glycerol. Glycerol enters glycolysis, a process that produces ATP. Fatty acids undergo beta-oxidation, yielding acetyl-CoA, which feeds into the citric acid cycle and oxidative phosphorylation, the major ATP-producing pathways in the cell.</p> Signup and view all the answers