Exam 2 - CH 5-7 Flashcards
Functions of fat in the body
- Energy fuel
- Energy stores
- Emergency reserve
- Padding
- Insulation
- Cell membranes
- Raw materials
Functions of fat in foods
- Nutrients
- Transport
- Energy
- Sensory appeal
- Appetite
- Texture
- Satiety
types of lipids
- Triglycerides
- Phospholipids
- Sterols
Structures of lipids
Carbon bonded with hydrogen
- Full = saturated
- Empty spaces = unsaturated
Functions of Lipids
- long-term energy storage
- act as structural components of cell membranes
- provide insulation
Lipid Digestion in:
- Mouth
- Stomach
- Liver & Gallbladder
- Pancreas
- Small intestine lining
- Inside the intestinal cell
- Mouth: lingual lipase : fat becomes tiny droplets
- Stomach: Gastric lipase: Minimal digestion
- Liver and gallbladder: Bile : Emulsifies fat soluble compounds
- Pancreas: pancreatic lipase: Triglycerides broken down into monoglycerides, diglycerides and glycerol
- Small intestine lining: Emulsified bile: Absorption of Micelles into the intestinal wall (cholesterol, fat soluble vitamins)
- Inside the intestinal cell: Chylomicron: Resynthesis of TG and packaging of lipids into a chylomicron and dumped into lymph system
Health Benefits and problems associated with lipids
Risks:
- Saturated and Trans Fat raise LDL cholesterol
- Dietary cholesterol has a minimal effect on blood cholesterol in most individuals
- High CHO diets raise VLDL’s
Benefits:
- Lower blood pressure
- Prevent cancer
- Strengthens cell membranes
- Brain function and vision
saturated lipids
- all single bonds
- solid at room temp.
- ex: butter, wax, blubber
Monounsaturated lipids
1 double bond
polyunsaturated fatty-acids
Two or more double bonds
What minimizes nutrient losses during food storage and preparation?
- Heat
- Cooking
- Air
- Light
- Acidity
- Freezing (not much loss)
Why are plant oils hydrogenated?
When hydrogen is added to plant oil to make it more solid and spreadable at room temperature
Health implications of trans-fat
- Raise your bad (LDL) cholesterol levels
- Lower your good (HDL) cholesterol levels
- Increases your risk of developing heart disease and stroke.
- Higher risk of developing type 2 diabetes
Recommended fat intake from the Dietary Guidelines for Americans
Total fat: 20-35% of calories
- Saturated fat: < 10%
- Trans fat: Limited trans fat
- Polyunsaturated fatty acids: includes oil
structure of proteins
- primary, secondary, tertiary, quaternary
- amino acids held together by peptide bonds
Recommended fat intake from the AMDR
20-35%
Explain why adequate amounts of amino acids are required for protein synthesis
Nitrogen is the building block of protein. Without these nutrients, our bodies can’t make the proteins needed to do work.
Protein digestion
Denaturation by stomach acid and enzymatic digestion in the stomach and small intestine turn strands to amino acids, dipeptides, and tripeptides.
Protein absorption
- cells all along small intestine absorb single amino acids
- enzymes on the cells’ surfaces split dipeptides and tripeptides into single amino acids and the cells absorb them too
- circulating in the bloodstream, carried to the liver where they are used or released into the blood
Protein metabolism
the liver acts as a storage place and assists in both protein anabolism and catabolism
Foods in term of protein amount and quality
- High quality proteins provide enough of all the essential amino acids needed by the body to create its own working proteins.
- Limit consumption of amino acids
Complementary proteins
two or more proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other
Roles of protein in the body
- Growth and maintenance
- Antibodies (Immune)
- Acid/base balance
- Blood clotting
- Cellular and organ system function (enzyme, hormones, and other compounds)
- Transport
- Fluid and electrolyte balance
- Energy and glucose
Nitrogen Balance
The amount of nitrogen consumed compared with the amount excreted.
- Basis of protein recommendations
What is the AMDR for protein?
10-35% of calories
Consequences of too much protein
excess protein is turned to glucose or fat
Consequences of too little protein
- Acute protein malnutrition (bulging stomach aka edema)
- Long term protein malnutrition (no muscle on body)
Celiac disease
(include what happens in the digestive tract, the consequences, how its diagnosed, and what foods to avoid)
Strengths of vegetarian diet
- Lower risks of chronic diseases
- Helps maintain a healthier body weight
- Often have increased intakes of whole grains, vegetables, fruits, etc.
- Lowers blood pressure
- Could be linked with preventing cancer
Limitations of Vegetarian diet
- Iron and zinc are less readily absorbed from vegan sources
- Lack of energy due to lack of B12
Difference between fat & water soluble vitamins
Water:
- Easily absorbed and excreted
- Foods that supply them must be consumed frequently
- Easily lost or destroyed during food preparation and processing
- C and B
Fat:
- Stored in the liver until needed by the body
- Do not need to consume everyday
- A, D, E, K
Vitamin A (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
- Cell differentiation
- Maintenance of keratin
- Growth and reproduction
- Immunity
- Vision
Fat soluble vitamin
Beta Carotene
Food Sources
-Orange and green leafy foods, milk
Toxicity: (acute) nausea, vomiting, headache
Deficiency: night blindness, impaired bone growth
Vitamin D (include food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
-Hormone that regulates blood
calcium.
-Calcitriol (acts at genetic level)
Fat soluble vitamin
Food Products
-Sunlight, fish products, milk
Toxicity: elevated bold calcium,
calcification of soft tissues
Deficiency: abnormal bone growth (resulting in rickets), osteomalacia
Vitamin E (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions
- Antioxidant in cell membranes
- Stabilizes free radicals
Fat soluble vitamin
Food Sources
-Found in oils, legumes and nuts, some vegetables
Toxicity: Augments the effects of anti clotting medication
Deficiency: Red blood cell breakage, nerve damage
Vitamin K (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
- Blood clotting (protein)
- Bone matrix proteins
Fat soluble vitamin
Food sources:
- Green leafy vegetables
Toxicity: opposes the effects of
anit-clotting medication
Deficiency: Hemorrhage, abnormal bone formation
Vitamin B12 (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
- Needed in cell synthesis
- Maintain nerve cells
Food sources:
- Animal products
Water soluble Vitamin
Deficiency: Anemia, numbness, fatigue, memory loss
Toxicity: None reported
Vitamin C (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
- Formation of connective tissue
- Wound healing
- Antioxidant
- Enhances iron absorption
Water soluble vitamin
Food sources: Vegetables, fruits
Deficiency: Scurvy, fatigue, bleeding gums
Toxicity: Nausea, kidney stones, diarrhea, destruction of red blood cells
What minimizes nutrient losses during food storage and preparation?
- Heat
- Cooking
- Air
- Light
- Acidity
- Freezing (not much loss)
Riboflavin (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Vitamin B2
Functions:
-Energy metabolism
Water soluble vitamins
Food sources:
- Protein
- Dairy
- Vegetables
Deficiency: cracks at corner of mouth, painful tongue, sore throat
Toxicity: none
Niacin (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
B3
Functions:
-Energy metabolism
Water soluble vitamin
Food sources:
- Protein (meat)
- Vegetables
Deficiency: Pellagra, flakey skin when exposed to sunlight
Toxicity: Hives, blurred vision, liver damage
Thiamin (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
-Energy metabolism
Water soluble vitamin
Food sources:
- Enriched grains
- Vegetables
- Protein foods
Deficiency: Muscle weakness, heart failure
Toxicity: none
B6 (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
Functions:
- Needed in amino acid and fatty acid metabolism
- Makes hemoglobin for red blood cells
Water Soluble Vitamin
Food Sources:
- Protein
- Fruits
- Vegetables
Deficiency: Anemia, depression, confusion, abnormal brain wave pattern
Toxicity: Depression, fatigue, impaired memory
Biotin (food sources) (characteristics) (fat or water soluble) (Deficiency & Toxicity)
B vitamin; a coenzyme necessary for fat synthesis and other metabolic reactions.
Who might benefit from multivitamin-mineral supplements
multivitamin-mineral supplements
- People with nutrient deficiencies
- Pregnant & Lactating women
- Newborns
- Diets limiting food
- Elderly
- Strict vegetarians
- Alcoholics
Guidelines for selecting supplements
- Choose type
- Read labels
- Target your needs
- Choose rational doses
- Remember you are eating foods too
- Quality
- Avoid marketing traps
Lipid Absorption
lacteals in small intestine absorb dietary lipids that are not absorbed by the blood capillaries
Lipid Transport
Lipids are transported in combination with proteins
