Introduction to Human Nutrition: Macronutrients

These flashcards cover key concepts about macronutrients, their digestion, absorption, and related health aspects in human nutrition.

What are the macronutrients essential for human nutrition?

Carbohydrates, Fats, and Proteins.

What role does nutrition play in disease prevention?

Nutrition helps prevent and manage diseases.

What is the glycemic index (GI)?

A measure of how a carbohydrate-containing food affects blood glucose levels.

What constitutes a monosaccharide?

A simple sugar molecule with 4-6 carbon atoms.

Give two examples of disaccharides.

Sucrose and Lactose.

What are polysaccharides?

Long chains of monosaccharides, more than ten units arranged in complex structures.

What is the primary role of carbohydrates in the body?

To supply energy and dietary fiber.

What are the two types of dietary fibers?

Soluble and Insoluble fibers.

What is the function of dietary fats?

They provide energy, insulation, and are structural components.

Define essential amino acids.

Amino acids that cannot be synthesized by the body and must be obtained from diet.

What are the main types of lipids?

Fatty acids, Phospholipids, Sterols.

Describe the structure of fatty acids.

A hydrocarbon chain capped by a methyl group and a carboxylic acid group.

What type of bond characterizes saturated fatty acids?

They contain only single bonds between carbon atoms.

What is the primary biochemical role of proteins?

They serve as building blocks and functional molecules in the body.

How are disaccharides formed?

By the bonding of two monosaccharides through a glycosidic linkage.

What does the term 'macronutrients' refer to?

Nutrients required in large amounts, such as carbohydrates, fats, and proteins.

What are the storage forms of carbohydrates in the body?

Glycogen.

How do bile salts aid in fat digestion?

They emulsify fats to form micelles that facilitate enzymatic breakdown.

What is a common source of omega-3 fatty acids?

Oily fish and certain plant oils.

Name a non-glycemic effect of carbohydrates.

Promoting dental health through increased salivation.

Which nutrient is crucial for the formation of neurotransmitters?

Amino acids.

What is the significance of sodium-linked glucose transporters?

They transport glucose into intestinal cells against its concentration gradient.

What is the process of carbohydrate digestion?

It involves breaking down complex carbohydrates into simple sugars.

Which part of the digestive system absorbs monosaccharides?

Small intestine.

What type of bond connects amino acids in proteins?

Peptide bonds.

What role do antioxidants play in the body?

They combat oxidative stress by neutralizing free radicals.

Give an example of a water-soluble vitamin.

Vitamin C.

What are the calorie-providing nutrients?

Carbohydrates, fats, and proteins.

What is the metabolic fate of fructose after absorption?

It is converted into glucose, glycogen, lactic acid, or fat in the liver.

What type of vitamins are fat-soluble?

Vitamins A, D, E, and K.

What happens to non-starch polysaccharides in the gut?

They either remain unchanged or are fermented to produce short-chain fatty acids.

How do HDLs function in fat transport?

They collect free cholesterol from peripheral tissues.

What is the primary structure of a protein?

The linear sequence of amino acids in a polypeptide chain.

What distinguishes essential from non-essential amino acids?

Essential amino acids must be obtained through diet, non-essential can be synthesized.

What are the characteristics of trans fatty acids?

They have a straight chain structure and are associated with negative health impacts.

What mineral is associated with preventing goitre?

Iodine.

How does chewing and salivation aid digestion?

It mechanically breaks down food and begins enzyme action.

What is the metabolic role of cholesterol?

It is involved in membrane structure and hormone synthesis.

How are fats transported in the body?

In lipoprotein complexes such as chylomicrons, VLDLs, LDls, and HDLs.

What type of polysaccharides does cellulose represent?

Non-starch polysaccharides resistant to human digestion.

Describe the absorption mechanism of amino acids.

Passive diffusion or sodium-dependent active transport.

What is the energy yield of protein metabolism?

4.2 kJ (1 kcal) per gram of protein.

What structural role do phospholipids play?

They form the bilayer of cell membranes due to their amphiphilic properties.

What health issue is linked with increased saturated fat intake?

Cardiovascular disease.

How does dietary fiber contribute to health?

It promotes gut health and regular bowel movements.

What does the term 'glycaemic effect' describe?

The impact of carbohydrates on blood glucose levels post-consumption.

What is the action of salivary amylase?

It begins carbohydrate digestion in the mouth.

Identify a disease associated with thiamin deficiency.

Beri Beri.

What occurs during protein digestion in the stomach?

Pepsin breaks polypeptides into smaller chains.