Triglycerides and Protein Metabolism

This set of flashcards covers the key concepts related to triglycerides, protein metabolism, and dietary advice for athletes.

What are the characteristics that all lipids share?

All lipids are hydrophobic and composed primarily of carbon and hydrogen.

How do saturated, monounsaturated, and polyunsaturated fats differ?

Saturated fats have no double bonds, monounsaturated fats have one double bond, and polyunsaturated fats have multiple double bonds.

What are the differences between cis and trans fats?

Cis fats have hydrogen atoms on the same side of the double bond, while trans fats have them on opposite sides.

How do the omega and delta systems for naming fatty acids differ?

The omega system counts from the methyl end, while the delta system counts from the carboxyl end.

Why must essential fatty acids be provided by the diet?

Essential fatty acids cannot be synthesized by the body and are necessary for various bodily functions.

How do the 3 classes of fatty acids affect blood levels of cholesterol?

Saturated fats raise LDL cholesterol, monounsaturated fats can lower LDL cholesterol, and polyunsaturated fats can lower both LDL and total cholesterol.

What are examples of foods that contain hidden fats?

Processed foods, baked goods, and some salad dressings often contain hidden fats.

Name 3 foods that contain monounsaturated fats, saturated fats, and polyunsaturated fats.

Olive oil (monounsaturated), butter (saturated), and flaxseeds (polyunsaturated).

What are 3 functions of triglycerides?

Energy storage, insulation, and protection of organs.

Under what conditions is fat used as the main fuel in the body?

During prolonged, low-intensity exercise or fasting.

What roles do essential fatty acids play in the body?

They are involved in cell membrane structure, hormone production, and anti-inflammatory processes.

What is the main structural difference between phospholipids and triglycerides?

Phospholipids contain a phosphate group, while triglycerides consist of three fatty acids.

What are the main functions of phospholipids?

They form cell membranes and act as emulsifiers.

How are phospholipids used in the food industry?

They are used as emulsifiers in products like salad dressings and margarine.

What is the main structural difference between sterols and triglycerides?

Sterols have a rigid ring structure, while triglycerides consist of fatty acid chains.

What are the main functions of sterols?

Sterols play a role in cell membrane structure and the synthesis of hormones.

What are 2 dietary sources of cholesterol?

Animal products such as eggs and meats.

What are the recommendations regarding total fat intake?

Total fat intake should be 20-35% of total daily calories.

What happens to blood LDL and triglyceride levels when saturated fat intake is replaced with polyunsaturated fats?

LDL and triglyceride levels typically decrease.

What is the role of cholecystokinin in the digestion of lipids?

Cholecystokinin stimulates the release of bile and pancreatic enzymes for fat digestion.

What is the role of bile in fat digestion?

Bile emulsifies fats, aiding in their digestion and absorption.

How does the chain length of a fatty acid affect absorption?

Shorter chain fatty acids are absorbed more quickly than long-chain fatty acids.

How are lipids carried in the blood?

Lipids are transported in the blood by lipoproteins.

How do chylomicrons, LDL, VLDL, and HDL differ in their composition?

Chylomicrons are rich in triglycerides, LDL primarily carries cholesterol, VLDL contains triglycerides, and HDL is rich in proteins.

What role do apolipoproteins play in lipid metabolism?

Apolipoproteins help stabilize lipoproteins and serve as recognition sites for cell receptors.

What determines if LDL is metabolized by the receptor pathway or the scavenger pathway?

The LDL particle size and presence of oxidized LDL determine the pathway.

What role does HDL play in cardiovascular disease?

HDL helps remove cholesterol from cells and transport it to the liver for excretion.

What is the risk of eating a diet that is low or high in omega-3 fatty acids?

A low intake can lead to inflammation, while a high intake can reduce the risk of heart disease.

What risk factors for cardiovascular disease can be modified by lifestyle changes?

Diet, physical activity, smoking, and weight can all be modified.

What are the risks and benefits of trans fatty acids?

Trans fats can raise LDL cholesterol levels but may improve shelf life in processed foods.

What health conditions are associated with diets high in total fat?

Obesity, cardiovascular disease, and certain cancers.

What are 3 ways of assessing protein quality?

Biological value, protein efficiency ratio, and amino acid score.

Why does egg protein have a high biological value (BV)?

It contains all essential amino acids in proportions that meet human needs.

Why is it important to use protein foods with high biological values with patients who have kidney disease?

High BV proteins provide essential amino acids with lower protein intake requirements.

What factors affect the protein quality of a food?

Amino acid composition, digestibility, and processing methods.

When is it important to be in positive nitrogen balance?

During periods of growth, pregnancy, or recovery from illness.

What situations increase the risk of being in negative nitrogen balance?

Malnutrition, severe illness, or injury.

During what stage of the life cycle are people generally in nitrogen equilibrium?

In adulthood, when body protein is balanced.

Name 4 enzymes that are involved in protein digestion and absorption and describe their action.

Pepsin (breaks down proteins in the stomach), trypsin and chymotrypsin (break polypeptides in the small intestine), and carboxypeptidase (removes amino acids from the carboxyl end).

What are the end products of polypeptide digestion?

Amino acids, dipeptides, and tripeptides.

What are 3 functions of proteins?

Structural support, enzymes, and transport molecules.

How do proteins help maintain fluid balance?

Proteins help control osmotic pressure, preventing fluid from leaking into tissues.

How do proteins contribute to immune function?

Proteins form antibodies that help fight infections.

What is glycogen loading?

A strategy that increases glycogen stores in muscles before endurance events.

What is Relative Energy Deficiency in Sport (REDS)?

A condition where athletes don't consume enough energy relative to their needs, affecting health and performance.

What is an ergogenic aid?

Substances or techniques used to enhance athletic performance.

When should supplements be used?

When dietary intake is insufficient to meet nutritional needs.

Should all athletes take a supplement?

Not all athletes need supplements; it depends on their dietary intake and specific needs.

Why are some amino acids classified as essential and others as nonessential?

Essential amino acids cannot be synthesized by the body and must be obtained from food.

What does the term limiting amino acid mean?

The essential amino acid present in the smallest amount relative to need.

How are the amino acids in a protein linked together?

Amino acids are linked together by peptide bonds.

Why is the structure of a protein important?

The structure determines a protein's function and activity.

What effects does denaturation have on a protein?

Denaturation alters a protein's structure and function, typically rendering it inactive.