Macronutrients Flashcards
What are the 6 classes of nutritents?
- Carbs
- Protein
- Lipids
- Vitamins
- Minerals
- Water
How many calories per gram are in 1 carb?
4 calories/gram
What are the 3 types of carbs?
- Monosaccharides
- Oligosaccharides
- Polysaccharides
3 types of monosaccharides
- Glucose
- Fructose
- Galactose
What does the body do with glucose?
- Used as energy in cellular metabolism
- Stored as glycogen in liver and muscle
- Converted to fat for later use (triacylglyceral)
What does the body do with fructose and galactose?
converts them to glucose for use in energy metabolism
What does galactose combine with to form?
Combines with glucose to form lactose in mammary glands of lactating animals
What are oligosaccharides made of?
2-10 monosaccharides
What are 3 types of oligosacchrides?
- Disaccharides
- Lactose
- Maltose
What is sucrose?
- disaccharide
- Sucrose = glucose + fructose
- Table sugar
What is lactose?
- disaccharide
- Milk = glucose + galactose
What is maltose?
- disaccharide
- beer and germinating seeds like barely
- glucose + glucose
What are polysaccharides?
10+ monosaccharides
What are 2 types of polysaccharides?
- Plant polysaccharides = starch, fiber
2. Animal polysaccharides = glycogen
What is starch?
storage form of carbohydrates in plants
-corn, potatoes, bread, beans
What are 2 types of starch?
- Amylose
2. Amylopectin
What is the difference between amylose starch and amylopectin starch?
Amylose is a long straight chain while amylopectin is a highly branched monosacchride
What is dietary fiber?
Plant material that is not digestible by human GI tract enzymes
-leaves, stems, fruit coverings
What is the most abundant dietary fiber?
Cellulose
What is cellulose?
Main component of plant cell walls found in carrots, celery, broccoli, etc
What does insoluble fiber do?
- Promote regular bowel movement
- Promote Microbial proliferation
- Lower risk of colon cancer
What are some types of insoluble fiber?
- Cellulose
- Lignin
- Hemicelluloses
What does microbial proliferation do for the body?
- Detoxifies
2. Reduces activity of enzymes that catalyze conversion of procarcinogens to carcinogens
What does soluble fiber do?
- Delays gastric emptying
- Delay glucose absorption causing a lower blood glucose
- Lower LDL cholesterol
How does soluble fiber lower LDL cholesterol?
- Bind fecal bile acids and increase excretion of bile-acid cholesterol
- Prevent dietary fat and cholesterol absoprtion
- Converts fermentable oligosaccharides to short chain fatty acids
What is an adequate intate of fiber per day?
Women- 25 grams
Men - 38 grams
What is glycogen?
Stored form of carbs in muscle and liver
What is the importance of glycogen for the body?
Provides major carb supply for active muscles
Glycogenesis
Glucose to glycogen
Glycogenolysis
Glycogen to glucose
Gluconeogenesis
Glucose synthesis of non-carbohydrate nutrients like lactate, pyruvate, glycerol, amino acids
What are the 4 roles of carbs in the body?
- Energy source
- Protein sparer
- Metabolic primer for fat oxidation
- Fuel for CNS
What is the recommended in take of carbohydrates per day?
45-65% of calories should be from carbs
How many calories per gram do lipids provide?
9 calories per gram
What are the 3 lipid groups?
- Simple
- Compound
- Derived
What are simple lipids?
Triacylglycerols
What do triacylglycerols consist of?
1 glycerol - 3 carbon backbone
3 fatty acid chains
Why does triacylglycerols synthesis increase following a meal?
- Food absorption increases blood levels of triacylglycerols
- High levels of circulating insulin facilitate isynthesis
What is lipolysis?
Breakdown of triacylglycerols which yields 1 glycerol and 3 fatty acid chains
What causes lipolysis?
- Low-to-moderate intensity exercise
- Low-calorie dieting or fasting
- Cold stress
- Prolonged exercise that depletes glycogen stores
What makes a fatty acid saturated?
Carbon atoms are “saturated” with hydrogen
Where are saturated fats found?
- Animal products mainly
2. Plant sources- coconut oil, vegetable shortening
What makes a fatty acid unsaturated?
One or more double bonds along the main carbon chain
What are the 2 types of unsaturated fatty acids?
- Monounsaturated- canola oil. oil in nuts
2. Polyunsaturated- sunflower or corn oil
What are the 2 essential fatty acids?
- Polyunsaturated when they come from dietary sources not animal cells
- Alpha-linolenic acid (ALA)- omega 3 vegetable oils
What is the importance of omega-3 fatty acids?
Crucial role in brain function and normal growth and development
Also may reduce risk of heart disease, inflammatory disease, Alzheimer’s, dementia, depression,
How many servings of omega-3’s are recommended per week?
2 servings
In sardines, salmon, tuna
How are trans fatty acids formed?
One hydrogen atom along the carbon chain moves from its natural position to opposite side of bond
How are hydrogenated oils formed?
add hydrogen to liquid oils and form solid fat
What do trans fatty acids do to the body?
Increase LDL cholesterol and decrease HDL cholesterol
What do food labeling rules allow with trans fat?
0.5g of trans fat per serving can be claimed as zero
What are the 4 functions of phospholipids?
- Interact with water and lipid to modulate fluid movement across cell membranes
- Maintain structural cell integrity
- Blood clotting
- Provide structure to insulating sheath surrounding nerve fibers
What type of lipid are HDL and LDL cholesterol?
Lipoproteins which is a compound protein
What are glycolipids?
fatty acids bound with carbs and nitrogen to surround nerves and brain tissue
How does the body gain cholesterol?
Diet, or cellular synthesis
What is the function of cholesterol?
Building plasma membranes, precursor in synthesizing vitamin D and hormones
What are the recommended lipid intake per day?
20-35% of total calorie intake
1. <300mg cholesterol
What are essential amino acids?
Body cannot produce and needs to be consumed
What are complete proteins?
Foods that contain all the essential amino acids
- animal products
- eggs best source
What are incomplete proteins?
Food that lacks one or more essential amino acids
-plant sources
What are some complementary proteins?
- Grains
- Legumes
- Dairy
- Seeds
What are the 7 roles of protein in the body?
- Catalysts - enzymes
- Messengers - hormones
- Structural elements- actin and myosin
- Immunoproteins
- Transporters- hemoglobin
- Buffers
- Fluid balancers
What are the fats of amino acids after deamination occurs?
- Gluconeogenesis
- Energy source
- Fat synthesis
When is positive nitrogen balance a good thing?
- Growing children
- Pregnancy
- Recovery from illness
- Resistance training
When does negative nitrogen balance occur?
Fever, burns, dieting, and starvation
What is the recommended amount of protein per day?
10-35% of total calories
Men- 59 grams/day
Women- 44 grams/day