Ch. 2 Carbohydrates, Lipids, and Protein

Nonessential amino acids

body CAN synthesize from other compounds already in body tissues at a rate to meet growth and tissue repair needs

1 kcal

equals the quantity of heat required to raise the temp. of 1kg of water to 1 deg. cel.

Complete proteins

exist in foods that contain all the essential amino acids in the quantity and correct ratio to maintain nitrogen balance

Phospholipids

fatty acid joined to phosphate group and nitrogen-containing molecule with four main functions

Glycolipids

fatty acids bound with carbohydrate and N2

Oligosaccharides

2-10 monosaccharides bonded chemically

Polysaccharides

3 to thousands of monosaccharide molecule linkages

Polypeptide

50 to more than 1000 amino acids joined together

A calorie or kilocalorie (kcal)

A measurement of food energy: a measure of heat, expresses a food's energy value.

1.2/1.8

Athletes who train intensely should consume between ___ and ___ g of protein per kg of body mass daily Example: an athlete weighing 100 kg requires 1.2 x 100 (120 g) to 1.8 x 100 (180 g) of protein in the daily diet Transposition: About 30 g = 1 oz; thus, 120 g = 4 oz and 180 g = about 6 oz

4,9,4,7

Average Atwater values: kcal/g carbohydrate kcal/g lipid kcal/g protein kcal/g alcohol

4.2 kcal/g 9.4 kcal/g 5.65 kcal/g

Average gross energy values: Carbohydrate = varies w/ arrangement of carb molecule atoms Lipid = varies w/ structural composition of molecule's fatty acids Protein = affected by protein type and relative N2 content.

15

Average person in U.S. consumes about ____% of total calories as saturated fatty acids; the equivalent of about 23 kg (51 lb) yearly

Monosaccharides

Basic unit of carbohydrates

2000/400/90-100

Body stores about kcal as carbohydrate Muscle stores about g glycogen Liver stores about g glycogen

Caloric Equality

Calories represent heat energy regardless of food source Examples: 300 kcal rocky road ice cream = 300 kcal lemons 450 kcal French fries = 450 kcal watermelon 600 kcal sushi = 600 kcal carrots 750 kcal snow peas = 750 kcal cottage cheese

fuel mixture

Carbohydrate Dynamics During Exercise: Intensity and duration determine ......

Saturated fatty acids

Carbon binds to the maximum number of hydrogens No double bonds; fatty acid chains fit close together Occur primarily in animal products and some plants Beef, lamb, pork, egg yolk

Simple lipids

Consist primarily of triacylglycerols/triglycerides (TAG) Major storage form of fat in adipocytes (fat cells) Contain one glycerol and three fatty acid chains Longer fatty acid chains contain less water-soluble molecules

Gross energy: 97/95/92

Proportion of food consumed actually digested and absorbed (i.e., coefficient of digestibility) average coefficient of digestibility: % for carbohydrates % for lipids % for proteins

Atwater General Factors

Provides a useful estimate of the net energy value of typical foods a person consumes

improves

Regular aerobic exercise profoundly ______________ long-chain fatty acid oxidation, particularly TAG to active muscle in mild-to-moderate-intensity exercise

1) glucose or dextrose (blood sugar) 2) Fructose (fruit sugar) 3) Galactose (milk sugar)

What are the three types of monosaccharides?

Increases harmful low-density lipoprotein cholesterol (LDL) Decreases beneficial high-density lipoprotein cholesterol (HDL)

What are the two health concerns with Trans fatty acids?

Starch and fiber

What are the two plant polysaccharides?

1) Food absorption increases blood levels of fatty acids and glucose 2) Relatively high levels of circulating insulin facilitate triacylglycerol synthesis

What are the two reasons why Triacylglycerol synthesis increases following a meal ?

Muscle glycogen

What glycogen storage during physical activity, provides the major carbohydrate supply for active muscles?

HDL vs LDL

___ protects against heart disease (unlike ___, which facilitates heart disease processes)

Essential Amino Acids: Amino acids that the body cannot synthesize

isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tyrosine, valine

Incomplete proteins

lack one or more essential amino acids

Lipoproteins

protein molecule joined with a triacylglycerol or phospholipid

Light- to moderate-intensity exercise

Fat Dynamics During Exercise: Fatty acids provide predominant energy source in light-intensity exercise Energy derives from equal amounts of carbohydrate and lipid in moderate-intensity exercise

Oxygen

Fat Dynamics During Exercise: Percentage contribution of macronutrient catabolism relates to _________ uptake of leg muscles during prolonged exercise

12,000 g (108,000 kcal) / 300 g (2700 kcal) / 4.0 g (36kcal) / 0.4 g (3.6 kcal) / total = 12,304 g (110,740)

Fat and Energy Content of the Body Adipose tissue: Intramuscular triacylgylcerols: Plasma Triacyglycerols: Plasma FFA: Total fat:

Moderate and prolonged exercise

Fat serves as main energy substrate during low-intensity exercise

Triacylglycerol Formation (Esterification)

Fatty acid substrate attaches to coenzyme A to form fatty acyl-CoA, which then transfers to glycerol (as glycerol 3-phosphate) In subsequent reactions, two more fatty acyl-CoAs link to the single glycerol backbone to form the composite triacylglycerol molecule Triacylglycerol synthesis increases following a meal

Simple Carbs

Glucose & Fructose

Sucrose

Glucose + Fructose table sugar, beet and cane sugar, brown sugar, sorghum, maple syrup, honey

Lactose

Glucose + Galactose found only in milk (milk sugar), not in plants

Maltose

Glucose + Glucose found in breakfast cereals, beer, and seeds

Direct Calorimetry

Gross energy value of foods: Burning food in a bomb calorimeter permits the direct quantification of the food's energy content.

Monosaccharides, Oligosaccharides, Polysaccharides

What are the three classifications of Carbohydrates?

Simple (neutral fats) Compound Derived

What are the three lipid groups?

Carbohydrates, Lipids, and Proteins

What are the three macronutrients?

Proteins

1-Constructed from linked amino acids 2-Contain about 16% nitrogen 3-Peptide bonds link amino acids together

Intense short-duration exercise

1-hr decreases liver glycogen 55%; 2-hr almost depletes liver + muscle glycogen

38g 25 g 30g 21 g 3:1

Daily Recommended Fiber Intake: Under age 50: men = women = Over age 50: men = women = Recommended ratio water-insoluble:soluble fiber =

20-35%

Daily Recommended Lipid Intake: _____% of total daily kcal (depending on lipid type) Substitute foods high in saturated fatty acids with fruits, vegetables, whole grains, fish, poultry, and lean meat

1) Gluconeogenesis 2) Energy source 3) Fat synthesis

Deamination provides carbon skeletons that follow one of three further diverse biochemical/metabolic routes in metabolism which are?

Trans fatty acids

Derived from partial hydrogenation of unsaturated corn, soybean, or sunflower oil

glycogen depleted state / Glycogen-loaded

Dynamics of Nutrient Metabolism: As submaximal activity progresses in a _____________, blood glucose levels fall and circulating free fatty acids increase dramatically compared with exercise under ____________ conditions

Negatively

Effect of Diet on Muscle Glycogen Stores and Endurance Performance: A carbohydrate-deficient diet depletes muscle and liver glycogen and _____________ affects performance in short-term anaerobic activity and prolonged intense aerobic activities

Net Energy Value of Macronutrients

Energy actually available to the body

Derived Lipids: Cholesterol

Exists only in animal tissue Does not contain fatty acids but shares some of lipids' physical and chemical characteristics High cholesterol diets can increase risk of coronary heart disease and atherosclerosis

Heat of Combustion

Heat liberated by oxidizing a specific food

Increases

Large __________ in protein synthesis occur during recovery from endurance and resistance exercise

1. Energy source and reserve Carries large quantities of energy per unit weight Transports and stores easily Provides an available energy resource 2. Protect vital organs (e.g., brain, heart, liver) 3. Thermal insulation 4. Vitamin carrier and hunger suppressor

Lipid's Role in the Body: Four major functions of lipids:

Unsaturated fatty acids

Monounsaturated contain one double bond Polyunsaturated contain two or more double bonds Linolenic acid is an example of an essential fatty acid

Increase

Most modes and intensities of exercise modestly ________ protein breakdown

Diabetes Fever Burns Dieting Growth Steroid use Recovery from illness

Negative nitrogen balance occurs during: (7)

Excretion

Nitrogen Balance: Requirement: nitrogen intake equals nitrogen

Child growth Pregnancy Recovery from illness During resistance exercise

Positive nitrogen balance occurs during: (4)

Must/deamination

Steps in Protein Metabolism: Nitrogen ____ be removed from amino acids prior to catabolism Process of ____________ (nitrogen removal) forms urea, which is eliminated as urine Deamination provides carbon skeletons that follow one of three further diverse biochemical/metabolic routes in metabolism Gluconeogenesis Energy source Fat synthesis

Glycogen

Storage carbohydrate in muscle and liver

Starch

Storage form of carbohydrate in plants

Lipids

Synthesized by plants and animals

LDL/HDL/HDL/LDL

The amount of ___ and ___ and their specific ratios (e.g., ___ ÷ total cholesterol; ___ ÷ HDL) and subfractions in plasma provide more meaningful indicators of coronary artery disease risk than total cholesterol

1) Low-to-moderate-intensity physical activity 2) Low-calorie dieting or fasting 3) Cold stress 4) Prolonged exercise that depletes glycogen reserves

Triacylglycerol Catabolism (Lipolysis): Mobilization of fatty acids via lipolysis predominates under four conditions:

Compound Lipids

Triacylglycerol components combined with other chemicals

15 g/kg BW

Upper limit for glycogen storage averages about

Disaccharide or double sugar

What are major oligosaccharides?

1)Energy source during intense exercise Energy derived from breakdown of blood-borne glucose and muscle glycogen 2)Protein sparer Helps preserve tissue protein 3)Metabolic primer Serves as "primer" for fat oxidation 4)Fuel for the central nervous system Serves as primary fuel for nerve tissue

What are the 4 carbohydrate's roles in the body?

1) R gorup or side chain 2) Central hydrocarbon group 3) NH2 (amine) group 4) COOH (Carboxyl) group

What are the FOUR common features of ALL amino acids?

1) Interact with water and lipid to modulate fluid movement across cell membranes 2) Maintain structural cell integrity 3) Play important role in blood clotting 4) Provide structural integrity to the insulating sheath surrounding nerve fibers

What are the FOUR main functions of creating phospholipids

300g/400-600g / 8-10g per kg body mass

What are the Recommended Carbohydrates Intake: 1) sedentary 70kg person = 2) Physically active person = 3) Athlete =

1) Blood plasma 2) Visceral (abdominal) tissue 3) Muscle 12-15%

What are the Three major sources of body protein: Constitutes up to __ to __% of body mass

1-Chylomicrons: transport Vitamins A, D, E, and K 2-High-density lipoprotein (HDL): "good" cholesterol 3-Very low-density lipoprotein (VLDL): transport TAGs to muscle and adipose tissue 4-Low-density lipoprotein (LDL): "bad" cholesterol

What are the four types of lipoproteins?

Maltose, Lactose, Sucrose

What are the three Oligosaccharides?

Become available as an energy source Form glycogen for storage in liver and muscle Convert to fat for later energy use

What are the three basic units of carbohydrates?

Glucogenesis/ gluconeogenesis/ glycogenolysis

What are the three carbohydrate conversions?

Glycogenolysis

glucose formation from glycogen (glycogen --> glucose)

Gluconeogenesis

glucose synthesis largely from structural components of noncarbohydrate nutrients (protein --> glucose)

Glucogenesis

glycogen synthesis from glucose (glucose --> glycogen)

Essential amino acids

indispensable; body CANNOT synthesize them so they must be consumed in foods

Fiber

occurs exclusively in plants

Tripeptide

three amino acids linked together

Dipeptide

two amino acids linked together