HUN2201 Chapter 4 Study Guide

Questions and Answers

Which carbohydrates are described as simple and which are complex?

Simple: Glucose, Fructose, Galactose; Complex: Glycogen, Starch (correct)

Simple: Galactose; Complex: Glucose, Sucrose

Simple: Sucrose; Complex: Fructose, Galactose

Simple: Maltose; Complex: Lactose, Starch

Describe the structure of a monosaccharide and name the three monosaccharides important in nutrition.

A monosaccharide has a ring structure composed of carbon, hydrogen, and oxygen atoms. The three important monosaccharides are glucose, fructose, and galactose.

Name the three disaccharides commonly found in foods and their component monosaccharides.

Sucrose (fructose + glucose), lactose (glucose + galactose), maltose (glucose + glucose).

In what foods are these sugars found?

Glucose is found in nearly all plant foods; fructose is commonly in fruits and saps; lactose is in milk; sucrose is in many fruits and some vegetables; maltose is in seeds. Signup and view all the answers

What happens in a condensation reaction?

Condensation combines two reactants to yield one product with the removal of water. Signup and view all the answers

What happens in a hydrolysis reaction?

Hydrolysis splits one reactant into two products with the addition of water. Signup and view all the answers

Describe the structure of polysaccharides and name the ones important in nutrition.

Polysaccharides are composed of many monosaccharides strung together. Important ones include glycogen, starch, and fibers. Signup and view all the answers

How are starch and glycogen similar and how do they differ?

Both are composed of glucose; they differ in the way their glucose units are linked: glycogen has highly branched chains, while starch has linear structures. Signup and view all the answers

How do fibers differ from other polysaccharides?

Fibers have bonds between monosaccharides that cannot be broken by human enzymes. Signup and view all the answers

Describe carbohydrate digestion and absorption.

Salivary amylase partially breaks down starch in the mouth; pancreatic enzymes digest starch to disaccharides; disaccharide enzymes split them to monosaccharides for absorption. Signup and view all the answers

What role does fiber play in the process?

Fiber slows eating, stimulates saliva flow, delays gastric emptying, slows absorption of carbs and fats, and attracts water in the intestine. Signup and view all the answers

What are the possible fates of glucose in the body?

It can be stored as glycogen, used for energy, or converted to fat. Signup and view all the answers

What is the protein-sparing action of carbohydrate?

Glucose can be used for energy, leaving protein available for its special functions. Signup and view all the answers

How does the body maintain blood glucose concentrations?

Hormones are secreted in response to fluctuations in blood glucose. Signup and view all the answers

What happens when blood glucose rises too high or falls too low?

If too high, the pancreas releases insulin; if too low, it releases glucagon to regulate glucose levels. Signup and view all the answers

Study Notes

Carbohydrates Overview

Carbohydrates are categorized as simple (monosaccharides and disaccharides) and complex (polysaccharides).
Simple carbohydrates include monosaccharides like glucose, fructose, and galactose, and disaccharides like sucrose, lactose, and maltose.
Complex carbohydrates include glycogen and starch.

Monosaccharides Structure and Importance

Monosaccharides have a ring structure consisting of carbon, hydrogen, and oxygen.
Important monosaccharides include glucose, fructose, and galactose.

Disaccharides Composition

Common disaccharides are sucrose (fructose + glucose), lactose (glucose + galactose), and maltose (glucose + glucose).
Sucrose is found in many fruits and vegetables, lactose is present in milk, and maltose is located in seeds.

Sugar Sources in Foods

Glucose is found in nearly all plant foods, while fructose is mainly in fruits and saps.
Galactose is generally not present in food separately.

Reactions in Carbohydrate Metabolism

A condensation reaction combines two reactants into one product while removing water.
A hydrolysis reaction breaks a reactant into two products by adding water.

Polysaccharides Structure and Nutritional Significance

Polysaccharides consist of many linked monosaccharides.
Key polysaccharides for nutrition include glycogen, starch, and dietary fibers.

Starch and Glycogen Similarities and Differences

Both starch and glycogen are glucose polymers.
Glycogen has highly branched chains of glucose, whereas starch has glucose units linked in straight chains or branching.

Fiber Characteristics

Fibers are unique polysaccharides as their bonds are not digestible by human enzymes.

Carbohydrate Digestion and Absorption

Digestion starts with salivary amylase in the mouth followed by pancreatic enzymes in the small intestine.
Disaccharides are broken down to monosaccharides on the intestinal cell surface.
Monosaccharides travel via capillaries to the liver, where galactose and fructose can be converted to glucose.

Role of Fiber in Digestion

Fiber promotes salivation, delays gastric emptying, slows carbohydrate and fat absorption, and attracts water in the large intestine to soften stools.

Fates of Glucose in the Body

Glucose can be stored as glycogen, utilized for energy, or converted to fat when carbohydrates are available.

Protein-Sparing Action of Carbohydrates

Carbohydrates provide energy, allowing protein to be available for its specific functions.

Blood Glucose Regulation

Hormones regulate blood glucose levels in response to fluctuations.
Elevated blood glucose triggers insulin release from the pancreas for glucose storage, while low blood glucose prompts glucagon release for glucose release into the bloodstream.

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Description

This study guide focuses on carbohydrates, distinguishing between simple and complex types. It covers important monosaccharides in nutrition and their structural characteristics. Perfect for students preparing for exams in nutritional science.

HUN2201 Chapter 4 Study Guide

Questions and Answers

Which carbohydrates are described as simple and which are complex?

Describe the structure of a monosaccharide and name the three monosaccharides important in nutrition.