Exam 2 - Chapter 4

Simple carbohydrates are commonly referred to as:

sugars

Where does chemical digestion of carbohydrates begin?

the mouth ??

What does a diet high in sugar cause?

tooth decay, hyperactivity in children, increase the levels of unhealthful lipids in our blood, increasing our risk for heart disease, may cause diabetes or obesity.

What is an oligosaccharide and what are some examples?

An oligosaccharide is a carbohydrate that contains 3 to 10 monosaccharides. Two of the most common oligosaccharides found in our diet are raffinose and stachyose. Raffinose is composed of galactose, glucose, and fructose. It is commonly found in beans, cabbage, brussels sprouts, broccoli, and whole grains. Stachyose is composed of two galactose molecules, a glucose molecule, and a fructose molecule. It is found in many beans and legumes.

What are the similarities and differences between Type 1 and Type 2 Diabetes?

Similarities - the liver releases glucose into the bloodstream, and high levels of glucose remain in the bloodstream. Difference - In type 1, Beta cells are damaged or destroyed, and little or no insulin is released into the bloodstream. In the absence of insulin, glucose is not taken up by cells. In type 2, Beta cells of pancreas release insulin into the bloodstream. page 141-142

Simple CHO Monosaccharides

Monosaccharides: single sugar 1. Glucose - essential energy to body other terms: dextrose, blood sugar 2. Fructorse - sweetest, fruits, honey 3. Galactose - seldom occurs in nature, found in milk sugar, made during lactation

Digestion in the Small intestine:

-major CHO-digesting enzyme is pancreatic amylase, breaks starch into short glucose chains and disaccharides - The final step occurs on the outer membranes of the intestinal walls (the microvilli) where specific enzymes work to break varying disaccharides into monosaccharides

Technique used by endurance athletes to increase glycogen stores.

eating carbs i think??

Condensation:

making chemical bond with water as a by-product

What are sugar alcohols? What products would you find them in?

mannitol, sorbitol, isomalt, xylitol. sugar alcohols are popular in sugar free gums, mints, and diabetic candies, they are less sweet than sucrose.

Simple CHO

All have the same chemical formula C6H12O6 structures are different

What are amylases?

An enzyme in saliva and pancreatic juice that breaks down starch into simple sugars

Resistance Starch:

escapes digestion and absorption. Acts like fiber, but does not lower cholesterol

Sucrose:

-Found in nature - fruits, veg, grains -Refined use - table sugar -white sugar, brown sugar, powder sugar

Transport:

-in the liver fructose and galactose are converted to glucose -all carbs turn to glucose for metabolism

Complex CHO: Polysaccharides

Composed of many monosaccharides linked together -starch -glycogen -fiber

Disaccharides: the two monosaccharides are linked by:

Condensation Reaction, water is a by-product

Simple CHO - Disaccharides

Disaccharides: 2 saccharides 1. Maltose: glucose + glucose 2. Sucrose: glucose + fructose 3. Lactose: glucose + galactose

What is insulin and where is it made?

Insulin helps the body to maintain blood glucose. Insulin is secreted by the beta cells of the pancreas. Insulin is transported in the blood to the cells of tissues throughout the body, where it stimulates special carrier proteins, called glucose transporters, located in cells. page 122

Absorption

Glucose and galactose are absorbed into the enterocyte by active transport -requires energy -requires carrier protein and sodium

Most common monosaccharides in our diet?

Glucose, fructose, and galactose are the three most common monosaccharides in our diet. Each of these contain 6 carbon atoms, 12 hydrogen atoms, ,and 6 oxygen atoms.

What is the glycemic index?

Glycemic Index refers to the potential of foods to raise blood glucose levels. Foods with a high index cause a sudden surge in blood glucose. This in turn triggers a large increase in insulin, which may lead to a big drop in blood glucose. Foods with a low glycemic index cause low to moderate fluctuations in blood glucose. page 124

What monosaccharides make up lactose, maltose, and sucrose?

Lactose - one glucose molecule and one galactose molecule Maltose - two molecules of glucose Sucrose - one glucose molecule and one fructose molecule. Because it contains fructose, it is the sweetest

Lactose:

Milk CHO

Name sources of fiber - soluble and insoluble.

Soluble - typically found in citrus fruits, berries, oat products, and beans. Pectins, fructans, gums, mucilages Insoluble - whole grains, wheat, rye, brown rice, lignins, cellulose, hemicelluloses.

What certain body parts can only use glucose for energy?

The eye, BRAIN, NERVE CELLS, RED BLOOD CELLS

What is lactose intolerance? How would that differ from a milk allergy?

The inability to digest lactose. The body does not produce sufficient amounts of the enzyme lactase in the small intestine. This differs from a milk allergy in that people with milk allergy experience an immune reaction such as hives or rashes, while with lactose intolerance, symptoms are limited to the GI tract. page 145

Major sources of carbohydrates include:

grains, legumes, tubers, fruit, vegetables, and dairy

Complex Cho - Oligosaccharides and Polysaccharides

on slides

Glucose transport in the body

on slides

Compare calorie content of table sugar versus honey

page 116

What are secretions found in the mouth that help digest carbohydrates?

salivary amylase

What are the benefits of increasing fiber in your diet?

- helps to prevent hemorrhoids, constipation, by keeping stool soft -reduces risk for diverticulosis -may reduce the risk of colon cancer -may reduce the risk of heart disease by delaying or blocking the absorption of dietary cholesterol into the bloodstream. -May lower the risk for type 2 diabetes -may enhance weight loss

Digestion of Carbohydrates:

-begin to breakdown in the mouth -digestion halts in stomach (too acidic) -resumes in small intestine (majority occurs here) Fiber: slow gastric emptying -provides feeling of satiety -may aid in weight loss

Impact of carbs on blood sugar levels

-can be measured using the Glycemic index -used to identify the effect a food will have on increasing blood sugar levels

Complex CHO

-consists of many glucose units -oligosaccharide: 3-10 monosaccharides -Raffinose - causes gas (beans, brussels sprouts, broccoli, whole grains) -Stachyose - also causes gas (beans and legumes)

Fructose absorbed by facilitated diffusion:

-no energy needed -stays in the intestine longer/increased time for metabolism -lower rise in blood sugar levels -large amounts may cause diarrhea -also must converted to glucose in the liver to be metabolized

Maltose:

-produced when starch breaks down -CHO digestion -Fermentation of plants - ETOH

Hydrolysis:

breaking chemical bond with water, main reaction for breaking down CHO