nutrition ch 3

A set of question-and-answer flashcards covering definitions, digestion, regulation, health effects, and disorders related to carbohydrates.

What are the three macronutrients?

Carbohydrates, proteins, and fats

Which macronutrient is the primary energy source for nerve cells?

Carbohydrates

What three elements compose carbohydrates?

Carbon, hydrogen, and oxygen

Name three major food groups that are good sources of carbohydrates.

Fruits, vegetables, and grains

Which carbohydrate is the most abundant in nature?

Glucose

How is glucose produced in plants?

Through photosynthesis

During photosynthesis, what three inputs combine to form glucose?

Sunlight energy, carbon dioxide, and water

How many molecules make up simple carbohydrates?

One or two molecules

Give the three monosaccharides.

Glucose, fructose, and galactose

Give the three disaccharides.

Lactose, maltose, and sucrose

What term is used for long chains of glucose molecules?

Polysaccharides (complex carbohydrates)

List the three main polysaccharides important in human nutrition.

Starch, glycogen, and fiber

In what form do plants store carbohydrates?

Starch

Which foods are rich sources of starch?

Grains, legumes, and tubers

What form of carbohydrate storage is found in animals?

Glycogen

Where is glycogen stored in the human body?

Liver and muscles

Is glycogen found in food?

No; it is not a dietary carbohydrate

Define dietary fiber.

The non-digestible part of plants

What is functional fiber?

Isolated or synthesized carbohydrate added to foods for health benefits

How is total fiber calculated?

Dietary fiber + functional fiber

How many kilocalories does 1 gram of carbohydrate provide?

4 kcal

Why is sufficient carbohydrate intake important for ketone prevention?

It prevents excess ketone production that can lead to ketoacidosis

What process produces new glucose from amino acids when carbohydrate intake is low?

Gluconeogenesis

List three health benefits of adequate fiber intake.

May reduce risks of colon cancer, heart disease, and type 2 diabetes; aids weight management and digestive health

Which enzyme begins carbohydrate digestion and where?

Salivary amylase in the mouth

Where does most chemical digestion of carbohydrates occur?

Small intestine

Name the pancreatic enzyme that digests starch in the small intestine.

Pancreatic amylase

Which three enzymes in the small intestine break down disaccharides?

Maltase, sucrase, and lactase

What condition results from insufficient lactase production?

Lactose intolerance

Which two hormones regulate blood glucose?

Insulin and glucagon

What does insulin do?

Helps cells take up glucose and stimulates the liver to store glucose as glycogen

What is the primary action of glucagon?

Stimulates glycogen breakdown and gluconeogenesis to raise blood glucose

Define hypoglycemia and give one common cause.

Low blood glucose; often caused by excessive insulin production

What is glycemic load?

Glycemic index multiplied by the amount of carbohydrate in a serving

What is the RDA for carbohydrate to fuel the brain?

130 grams per day

What percentage of daily calories should come from carbohydrates?

45–65%

State the Adequate Intake (AI) values for fiber for adult men and women.

38 g/day for men and 25 g/day for women

Name two negative effects of diets high in simple sugars.

Increase dental problems and raise LDL ('bad') cholesterol while lowering HDL ('good') cholesterol

What are the three types of diabetes?

Type 1 diabetes, Type 2 diabetes, and gestational diabetes

Describe Type 1 diabetes.

Autoimmune destruction of pancreatic beta cells leading to little or no insulin production and hyperglycemia; requires insulin injections

Describe Type 2 diabetes.

Body cells become insulin-resistant; often linked to obesity and inactivity; managed with lifestyle changes and sometimes medications