exam 2 carbs fats proteins

Photosynthesis

Plants combine carbon dioxide, water, and sunlight to make glucose.

Carbohydrate composition

Made of carbon, hydrogen, and oxygen; "carbo" = carbon, "hydrate" = water.

Glucose

The most important monosaccharide; main energy source for body cells.

130

How many grams of carbohydrates does the DRI recommend the average-sized person consume minimally each day?

Monosaccharides

Single sugars; glucose, fructose, galactose.

Fructose

"Fruit sugar"; sweetest monosaccharide; found in fruit, honey, table sugar, and added sugars.

Galactose

Rare in free form; found in lactose (milk sugar); converted to glucose by the liver.

Disaccharides

Double sugars; lactose, maltose, sucrose.

Lactose

Glucose + galactose; "milk sugar."

Maltose

Glucose + glucose; forms during starch breakdown and in germinating seeds.

Sucrose

Glucose + fructose; "table sugar"; found in sugar cane, sugar beets, fruits, vegetables.

Starch

Plant storage form of glucose; found in grains, legumes, root vegetables.

Glycogen

Animal storage form of glucose; highly branched; stored in liver and muscle.

Dietary fiber

Indigestible plant polysaccharides; human enzymes cannot break them down.

Soluble fiber

Dissolves in water, forms gels, fermentable; nourishes gut bacteria.

• lowers cholesterol,

• alleviates constipation

• Slows transit of food through the upper digestive tract

• Slows glucose absorption

Insoluble fiber

Does not dissolve in water;

• adds bulk to stool;

• supports digestive tract health.

• lowers risk of hemorrhoids

• Alleviates constiparion

Fermentable fiber

Fiber broken down by colon bacteria, producing beneficial short-chain fatty acids.

Carbohydrate role in diet

Provides energy for body tissues; brain and RBCs depend on glucose.

Refined carbohydrates

Should be limited; lack fiber, vitamins, and minerals.

Health benefits of fiber

• Lowers cholesterol,

• modulates blood sugar,

• aids digestion,

• supports gut health,

• reduces cancer risk,

• helps manage weight.

• Contributes to satiety

Best fiber sources

Whole plant foods: fruits, vegetables, legumes, whole grains.

Whole grains

Contain bran, germ, and endosperm; more nutritious.

Refined grains

Mostly endosperm; lower in nutrients and fiber.

Carbohydrate digestion

Starches and sugars broken into glucose for absorption.

Monosaccharide absorption

Enter bloodstream directly.

Disaccharide digestion

Must be broken down by enzymes into monosaccharides.

Lactose intolerance

Caused by low lactase enzyme; leads to gas, bloating, diarrhea.

Milk allergy

Immune reaction to milk proteins; different from lactose intolerance.

Glucose regulation

Insulin lowers blood sugar; glucagon raises blood sugar.

Glycogen storage

Muscles and liver store glucose as glycogen; liver releases glucose into blood when needed.

Glucose deficiency

Protein broken into glucose; fat converted to ketone bodies → ketosis.

Excess glucose

Stored as glycogen first; converted to fat if storage is full.

Glycemic response

How quickly blood glucose rises and falls after a meal.

Glycemic index

Scale of how strongly a food raises blood glucose.

Type 1 diabetes

Blood glucose remains high because insulin is lacking.

Type 2 diabetes

Blood glucose remains high because cells resist insulin,

• often associated with obesity

Hypoglycemia

Abnormally low blood sugar; often linked to diabetes mismanagement.

Carbohydrate intake recommendation

45-65% of daily calories.

Carbohydrate-rich foods

Breads, cereals, starchy vegetables, fruits, milk.

Added sugars

Provide energy but few nutrients; "empty calories."

Health risks of added sugars

Excess intake linked to obesity, heart disease, type 2 diabetes.

insoluble and doesn’t wash away in rain

Why is starch a better storage form for plants than free glucose?

Maltose

Which disaccharide is formed when starch is digested?

Ketosis

when carbohydrate intake is too low

• The body breaks down protein and fat for energy

Mineral deficiency

What is a risk of very-high-fiber diets in vulnerable groups? (children, elderly, malnourished)

Ketone bodies

Molecules produced from fat breakdown during low carbohydrate availability;

• can fuel the brain when glucose is low.

Alters blood lipids

When added sugar is consumed in excess of calorie need, it

Germ

nutrient-rich core of the grain, packed with oils, vitamins (especially B vitamins and vitamin E), minerals,

Bran

Part of the whole grain with fiber, B vitamins, and minerals.

Endosperm

Part of the grain with mostly starch some protein

25, 38

How many grams of fiber do the Dietary Reference Intakes suggest for adult women and men?

Maltose from starch

After chewing a piece of bread for a while you begin to experience a slightly sweet taste. This taste results from

Diabetes

• Frequent urination + increased thirst

• Symptoms of

Hypoglycemia

Irregular heartbeat shakiness, sweating, anxiety, hunger, and dizziness.

• symptoms of

Iron and water soluble vitamins

Enrichment refers to the addition of nutrients to a refined grain food product. What are the nutrients added during enrichment?

Fructose

Which sugar is converted to glucose in the liver?

Functions of lipids

• abundant fuel

• fat cushions tissues

• serves as insulation

• forms cell membranes

• serves as raw material

Lipids benefits

• provide abundant energy in small portions,

• enhance aromas and flavors, and

• increase satiety (help you feel full).

Triglyceride

A molecule made of three fatty acids attached to one glycerol;

• it is the primary storage form of fat in the body.

Saturated

Type of fat

• Filled with hydrogen, no double bonds, usually solid at room temperature.

Monounsaturated

Type of fat

• One double bond, liquid at room temperature.

Polyunsaturated

Type of fat

• More than one double bond, liquid at room temperature.

Phospholipids

Lipids that are key components of cell membranes,

• supporting structure and signaling.

Sterols

used in bile, vitamin D, sex hormones, and other compounds.

Function of plant sterols

• inhibit cholesterol absorption, potentially lowering blood cholesterol.

Fats in stomach

• separate from other food components due to limited digestion.

Glycerol and short-chain fatty acids

lipids that enter the bloodstream directly

Lipoproteins

Specialized transport vehicles that carry fats in watery body fluids.

carbohydrates

(Blank) are required for the complete breakdown of fat, or fat metabolism

Chylomicrons

Type of lipoprotein

• Transport dietary fats from intestines.

• Produced in small intestinal cells

Very low density

Type of lipoprotein

• Transport triglycerides from the liver.

Low density

Type of lipoprotein

• Carry cholesterol to tissues; high levels ↑ heart disease risk

High density

Type of lipoprotein

• Remove cholesterol from tissues; high levels ↓ heart disease risk.

saturated and trans

Fats that raise LDL cholesterol

dietary cholesterol

Fat that has minimal effect for most people.

Exercise

What can increase HDL mainly?

Essential fatty acids

fats the body cannot make:

• omega-6 (linoleic acid, arachidonic acid) and omega-3 (linolenic acid, EPA, DHA).

omega-6 and 3

Balancing (blank) levels helps maintain normal body functions, including

• inflammation control

• heart

• brain

• vision health.

Hydrogenation

A process that adds hydrogen to unsaturated vegetable oils,

• making them more saturated and solid.

hydrogenation

What process destroys the health benefits of unsaturated oils and creates trans-fatty acids.

trans fats

Like saturated fats, they increase heart disease and artery problems.

Hidden saturated fats

Meats and grain foods with added fats.

Avoid solid fats

These are ways to (blank)

• Choose seafood

• use unhydrogenated margarine

• cook with unsaturated oils

• Eat nuts

Debate on lipids

No biological mechanism fully explains how saturated fat causes atherosclerosis, though evidence shows replacing saturated fats with unsaturated fats reduces LDL and CVD risk.

Evidence on lipids

Replacing saturated fats with polyunsaturated fats lowers total and LDL cholesterol and reduces risk of heart disease and death from CVD.

Poor wound healing

symptoms associated with a diet deficient in essential polyunsaturated fatty acids

Saturation

Refers to whether or not a fatty acid chain is holding all of the hydrogen atoms it can hold.

Lecithin

Strong emulsifier and phospholipid

Coconut and palm

2 plant oils composed primarily of saturated fats

L acids

The DRI committee sets recommended intake levels for two types of essential fatty acids,

Omega 6

Essential fatty acid (EFA)

• Linoleic acid and arachadonic acid

• Vegetable oils and meat are a good source

• Generally consumed in excess in human diet

• Pro inflammatory effect

Omega 3

Essential fatty acid (EFA)

• linolenic acid, EPA, DHA

• Fatty fish and green leafy vegetables a good source

• Not as prevalent in diet

• anti inflammatory effect

• Vision and brain

• Reduce risk of heart disease

normal

70-99 ml/dl fasting blood glucose levels are considered ?

Prediabetes

100 - 125 ml/dl fasting blood glucose levels are considered ?

Diabetes

126 ml/dl and up fasting blood glucose levels are considered ?