Biology 101: Chapter 5 - Carbohydrates

Flashcards covering key vocabulary and concepts from the lecture notes on carbohydrates.

Carbohydrates

Nutrients that provide energy and often end in -ose

Simple Carbs

Sugars such as monosaccharides and disaccharides

Complex Carbs

Dietary starch, glycogen, and fiber

Monosaccharides

One sugar unit; the 3 most important are glucose, fructose, and galactose

Glucose (aka dextrose)

Found in fruits/veggies and is the main fuel source for many cell types

Fructose (aka fruit sugar or levulose)

Sweeter taste; found in fruit, honey, and a few veggies; body converts to glucose or fat

Galactose

Not usually found in foods, but is a component of lactose, a disaccharide

Maltose

Malt sugar, found in starchy grains, some fruit, honey

Sucrose

Table sugar, found in honey, maple syrup, carrots, pineapple; mostly consumed as refined sugar

Lactose

Milk sugar found in milk and some milk products

Nutritive Sweeteners

Contain carbs that provide energy (4 Cal/g); common additives in processed food (for flavor, appearance, preventing spoilage)

Sugar Alcohols

2 Cal/g; not completely absorbed in GI tract, don’t cause dental decay, used in sugar-free products, may cause diarrhea

Nonnutritive Sweeteners (aka artificial sweeteners)

Add sweetness with minimal/no Cal; listed as safe when consumed within acceptable daily intakes; many are high-intensity sweeteners

Starch

Storage form of glucose in plants; found in grains, some veggies, tubers

Glycogen

Storage form of glucose in animals; mostly made/stored in muscles/liver

Fiber

Not digestible by humans; may be fermented by gut microbiota

Soluble Fiber

Dissolves/swells in water and can help reduce blood cholesterol

Insoluble Fiber

Doesn’t dissolve/swell in water; helps with easier bowel movements

Salivary Amylase

Begins starch digestion in the mouth

Pancreatic Amylase

Continues breaking starch à maltose in sm. intestine

Maltase

Breaks maltose à glucose à absorbed into sm. intestine à liver

Sucrase and Lactase

Break sucrose and lactose and monosaccharides are absorbed in sm. intestine à liver à fructose/galactose à glucose

Insulin

Lowers blood sugar by making glycogen from glucose

Glucagon

Raises blood sugar by breaking down glycogen; stimulates liver/kidney to make glucose from some amino acids and stimulates fat breakdown à glycerol and fatty acids

Nonalcoholic Fatty Liver Disease

Liver can accumulate fat in people with insulin resistance or obesity or people that consume high amounts of sugar-sweetened drinks

Ketone Bodies

Cells having to use fat as the main energy source form more ketone bodies, due to incomplete breakdown of fat

Ketoacidosis

Ketones build up and acidify the blood; can occur if type I diabetes is not controlled well

Hyperglycemia

High levels of blood glucose that can damage nerves, blood vessels, and organs à kidney/heart disease, blindness, amputations

Type I Diabetes

Autoimmune disease in which the immune system attacks cells of the pancreas that make insulin (beta cells)

Type 2 Diabetes

Most common type; can make insulin, but either don’t make enough or target cells are insulin-resistant (glucose can’t get in)

Gestational Diabetes

Can develop after the 5th month of pregnancy

Hemoglobin A1c

Hemoglobin bound to glucose; used to measure blood glucose levels over time

Glycemic Index (GI)

Way to classify foods based on the rise in blood glucose compared to a standard

Glycemic Load (GL)

Grams of carbs in a food x food’s GI, divided by 100. More realistic because it indicates relative rise after eating a serving of food.

Hypoglycemia

Occurs when blood sugar levels are too low (<70 mg/dL) for energy needs of cells

Metabolic Syndrome

A set of signs/symptoms that together indicate a health problem; roughly 1/3 of Americans have it

Lactose Intolerance

Lack lactase to break down lactose; not completely broken down by the time it gets to lg. intestine à bacteria break it down à gas, bloating, cramps, diarrhea