Human Nutrition Chap. 4 CARBOHYDRATES

What are some benefits for fiber consumption?

- Helps prevent hemorrhoid a, constipation, and other intentional problems by keeping our stools moist and soft - Reduces the risk for diverticulosis, a condition that is caused in part by trying to eliminate small, hard stools - May reduce the risk of colon cancer - May reduce the risk of heart disease by delaying or blocking the absorption of dietary cholesterol in the bloodstream - May lower the risk for type two diabetes - May enhance weight loss, as eating a high-fiber diet causes a person to feel more full

What is the RDA of carbohydrates for average adults?

130 grams of carbohydrates per day

What two monosaccharides make the disaccharide Maltose?

2 Glucose molecules

What is a Disaccharide? Name some examples

A carbohydrate compound consisting of two monosaccharide molecules joined together. Examples include lactose, maltose and sucrose.

What is a polysaccharide? Name some examples

A complex carbohydrate consisting of long chains of glucose. Starch, glycogen, and fiber are examples of polysaccharide.

Define insulin

A hormone secreted by the beta cells of the pancreas in response to increased blood levels of glucose that facilitates uptake of glucose by body cells.

Define Complex Carbohydrates and give some examples

A nutrient compound consisting of long chains of glucose molecules such as starch, glycogen, or fiber. Technically any carbohydrates with three or more monosaccharides are considered complex carbohydrates.

Describe the difference between the two forms of starches: Amylose and Amylopectin

Amylose is a straight chain of glucose molecules while amylopectin is a highly branched chain of glucose molecules. Both forms of starch are found in starch-containing foods. Amylopectin's open branched structure increases the surface area and thus its exposure to the digestive enzymes which results in the rapid digestion of it. Which means that Amylopectin raises blood glucose more quickly than Amylose.

Describe Fiber: Cellulose

Cellulose is the main structural component of plant cell walls. Cellulose is a chain of glucose units similar to amylose. But unlike amylose, cellulose contains beta bonds that are not digestible by humans. Cellulose is found in whole grains, fruits, and legumes and other vegetables.

What is an oligosaccharide? Name some examples

Complex carbohydrates that contain three to ten monosaccharides. Some examples include raffinose and stachyose.

Describe the risks of consuming too many carbohydrates

Consuming too many carbohydrates can be linked to obesity, can cause an increase in sugars (because carbs breakdown into sugar) which can lead to any of the numerous risks that eating too much sugar can cause

Define Dietary Fiber

Dietary Fiber is the non digestible parts of plants that form the support structures of leaves, stems, and seeds.

What are the three distinctions of fiber?

Dietary fiber, functional fiber and total fiber

What are some functions of carbs in the body?

Fuel daily activity and exercise and fuels many metabolic processes by being our main energy source

Define Functional Fiber

Functional Fiber is the no digestible forms of carbohydrate that are extracted from plants or manufactured in the laboratory and have now health benefits. Functional Fiver is added to foods and is the form found in fiber supplements. Examples include Cellulose, guard gum, pectin, inulin, and psyllium

What two monosaccharides make the disaccharide Lactose?

Galactose and Glucose

What monosaccharides comprise the oligosaccharide Raffinose?

Galactose, Glucose, and Fructose

What two monosaccharides make the disaccharide Sucrose?

Glucose and Fructose

How does Glucose get digested in the Liver?

Glucose is absorbed across the enterocytes via active transport using a carrier protein saturated with sodium. This process requires energy from the breakdown of AtP.

What are some food sources of starch?

Grains (wheat, rice, corn, oats, and barley), legumes (peas, beans, and lentils), and tubers (potatoes and yams).

Describe Fiber: Gums

Gums contain galactose, glucronic acid, and other monosaccharides. Gums are a diverse group of polysaccharides that are viscous. They are typically isolated from seeds and are used as thickening, gelling, and stabilizing agents. Guard gum and gum Arabic are common gums used as food additives.

Why is HFCS a concern when used as an additive?

HFCS can cause: - obesity and weight gain - higher risk for type 2 diabetes - liver damage - elevated cholesterol and hypertension

How does the human body react to low blood glucose levels?

INSULIN SECRETION When blood glucose levels are low, the pancreas secretes the hormone glucagon from the alpha cells into the bloodstream. GLYCOGENOLYSIS Glucagon stimulates the liver to convert stored glycogen into glucose which is released into the blood and transported to the cells for energy. GLUCONEOGENESIS Glucagon also assists in the breakdown of proteins and the uptake of amino acids by the liver which creates glucose from amino acids

How does the human body react to high blood glucose levels?

INSULIN SECRETION When blood glucose levels increase after a meal, the pancreas secretes the hormone insulin from the beta cells into the bloodstream CELLULAR UPTAKE Insulin travels to the tissues. There, it stimulates glucose transporters within cells to travel to the cell membrane, where they facilitate glucose transport into the cell to be used for energy GLUCOSE STORAGE Insulin also stimulates the storage of glucose in body tissues. Glucose is stored as glycogen in the liver and muscles and is stored as triglycerides in adipose tissue

What digestive enzyme breaks down Lactose?

Lactase

Describe Fiber: Lignins

Lignins are no carbohydrate forms of fiber. Lignins are found in the woody parts of plant cell walls and in carrots and the seeds of fruits. Lignins are found in brands and other whole grains.

What digestive enzyme breaks down Maltose?

Maltase

What is a Monosaccharide? Name some examples

Monosaccharides consist of one sugar molecule, and the most common form is glucose but they also include fructose, galactose, and ribose.

Define Carbohydrates

One of the three macronutrients, a compound made up of carbon hydrogen and oxygenthat is derived from plants and is the main source of energy in humans. Carbohydrates can be split into two categories, simple and complex.

Describe Fiber: Pectins

Pectins contain chains of galacturonic acid and other monosaccharides. Pectins are found in the cell walls and intracellular tissues of many fruits and Barrie's. Pectins can be isolated and used to thicken foods, such as jams and yogurts

What are Simple Carbohydrates? Name some examples.

Simple carbohydrates are commonly referred to as sugars. These include mono and disaccharides. Fructose, galactose, ribose, lactose, maltose, and sucrose are all examples of simple carbohydrates.

What are resistant starches?

Starches linked by beta bonds are largely indigestible and are therefore called resistant starches.

What digestive enzyme breaks down Sucrose?

Sucrase

How does Fructose get digested in the Liver?

The absorption of Fructose takes longer than that of glucose or galactose. This slower absorption rate means that fructose stays in the small intestine longer and draws water into the intestines via osmosis. Fructose is essentially absorbed the same way as glucose though, across the enter yes via active transport using a carrier protein saturated with sodium. This process requires energy from the breakdown of ATP.

What is the Glycemic Index and what are other factors affecting it in regards to foods in GI value?

The glycemic index is a rating of the potential of odds to raise blood glucose and insulin levels. Some factors that affect the Glycemic Index in regards to foods include the type of carbohydrate, the way the food is prepared, and it's fat and fiber content.

Define Total Fiber

The sum of dietary fiber and functional fiber

What is the primary goal of carbohydrate digestion?

To break down polysaccharides and disaccharides into monosaccharides that can be converted to glucose

What are some NEGATIVE effects of too much/too little fiber consumption?

Too much: gas, bloating, and cramps in he abdomen Too little: same as too much

What monosaccharides compose the oligosaccharide Stachyose?

Two Galactose molecules, glucose, and fructose

What is the Difference between type 1 and type 2 Diabetes

Type 1 Diabetes is a disorder in which the pancreas cannot produce enough insulin and is usually a disorder born with. Type 2 Diabetes is a disorder in which body cells become less responsive to insulin, and is a disorder in which you aren't born with and is a direct consequence of consuming too much sugar.