Macronutrients Flashcards
Why is studying nutrition important?
health maintenance and disease management
Nutrient
any food constituent that helps support life
6 Categories of Nutrients
- Water
- Carbs
- Proteins
- Fats
- Vitamins
- Minerals
Is ATP a nutrient?
NO, it is energy but it is created within the body
What fraction of nutritional needs comes from water?
2/3 (two-thirds)
What fraction of nutritional needs comes from dry matter?
1/3 (one-third)
What percent of dry matter is energy yielding?
anywhere from 50-80%
What categories of nutrients yield energy?
carbs, fats, and proteins
What percent of dry matter is made up by vitamins?
0.2-0.3%
What percent of dry matter is made up by minerals?
2-3%
Basic Body Functions that need nutrients (5)
- Energy supply
- Structural components
- Temperature Control
- Enchancement/requirement for chemical rxns
- Transport of substances
Two Sources of Water
- Ingestion
- Metabolic
How much of the water requirement comes from metabolic sources?
5-10%
Amount of body water in obese patients compared to leaner patients
Obese patients = less body water
What % of total body mass is water?
40-80%
Do water requirements increase or decrease with age?
decrease (less uinary water loss and less surface area per unit of body weight)
What % water can be lost before becoming ill?
10%
What % water can be lost before death?
15-20%
4 Main Functions of Water
- Solvent
- Chemical Rxns
- Thermoregulation
- Structural
Factors that Affect Water Quality (3)
- Mineral content
- Nitrates/nitrites
- Bacterial contamination
Is coliform bacteria a pathogen itself?
no, it is an indicator that water may not be pathogen-free however
Total Dissolved Solids (TDS)
general indicator of water quality
Unacceptable level of TDS
greater than 7000 ppm
TDS level for humans and pets?
less than 500 ppm
4 Ways the body loses water
- Urination
- Defecation
- Evaporation
- Perspiration
Which has more concentrated urine - dogs or cats?
cats
3 Consequences of Water Intoxication
- Hemodilution
- Hyponatremia
- Edema in the brain
How is your daily water requirement related to your daily energy requirement?
Daily water requirement (mL/day) = Daily energy requirement (kCal/day)
(more or less equal to each other)
formula for carbohydrates (all composed of carbon, hydrogen, and oxygen)
Lactose
glucose + galactose
Sucrose
glucose + fructose
What type of polysaccharides are digesible and why?
starches (ex: amylose and amylopectin) and glycogen because they have alpha bonds
What types of polysaccharides are not digestible?
fibers (beta bonds)
Randle Cycle
glucose and fatty acids compete for oxidation and uptake in muscle and adipose tissue (aka glucose sparring)
Gelatinization of Starches Effect on Digestability
increases digestability
Primary Location for Carbohydrate Digestion
small intestine (various enzymes from the pancreas (amylase) and in the brush border)
5 Effects of Unabsorbed Carbohydrates
- High osmotic pressure (reducing water and mineral absorption)
- Abdominal distension
- Diarrhea
- Bacterial Overgrowth
- Overproduction of gas/flatuence
What is the main water source for desert animals?
metabolic
Endogenous Energy Stores
glycogen and fat
Metabolism of carbs to energy occurs via
glycolysis and TCA cycle
4 Examples of Metabolic ByProducts
- Non-essential AAs
- Glycoproteins
- Lactose
- Vitamin C
How does the body eliminate carbohydrates?
mainly carbon dioxide, water, and heat after oxidation in the body; flatulence (bacterial fermentation in intestinal lumen)
Xylose
used to test absorption in dogs
Lactulose
prebiotic and laxative; syntetic dissacharide (body doesn’t have enzyme to breakdown)
Glycoaminoglycan
polysaccharide often put in dietary supplements for joints
Oligosaccharides
prebiotics (support bacterial growth)
Resistant Starches
Increased deitary fiber
Reduce carb absorption –> reduce glucose levels –> lower glycemic index
Problem with too much resistant fiber?
Remains in intestinal lumen and messes with osmotic pressure so can decrease nutrient intake and absorption
What makes up an amino acid? (3)
- Carboxyl group (COOH)
- Alpha amino group (NH2)
- R group (unique)
How many AAs are commonly found in proteins?
20
Peptide Bonds
the bonds in amino acids
What makes an amino acid essential?
the body cannot synthesize [enough] AA so it needs to come from the diet
3 Ways AAs Hekp Body Function
- Structural components (elastin, collagen, keratin)
- Functional units [of muscle, enzyme, hormones, etc]
- Precursors
Do younger animals need more or less AAs?
more
How does the size of a meal affect protein concentration?
animals who eat large meals at once need lower protein concentrations/lower calorie foods
Maintenance Protein Requirement
dietar yprotein that much be consumed to replace obligatory nitrogen loss
Imbalance
AA required in protein synthesis is not available (but others are in excess)
Antagonism
AAs with similar structure
Protein Quality
refers to efficiency of converting AAs for use in the tissue
Factors that Affect Protein Quality
- Amount and Proportions of Essential AAs
- Imbalance/Antagonism
- Processing (lower digestability)
- Animal vs. Plant Source
What source of protein is typically more digestable - animal or plant?
animal
Peptidases
secreted by the pancreas and in intestinal mucosa to breakdown/digest smaller peptides and AAs
Digestion of large polypeptides in the stomach is done by what?
pepsin and HCl
What happens to unabsorbed AAs?
used in bacterial fermentation and increases fecal odor
How is ammonia excreted from the body?
urea (via the urea cycle)
3 Important AAs in Vet Med
- Taurine
- Arginine
- Glutamine/Glutamate
Taurine is essential for what species?
cats
Functions of Taurine
- Absorption of dietary fats
- NT in the CNS for body temperature and brain development
- Heart and retina maintenance
- Reproduction
Why is taurine essential for fat absorption in cats?
tauine is the only AA that binds to bile acids
Arginine
essential AA important in the urea cycle; cats are sensitive to deficiencies
How can taurine deficiencies in cats lead to DCM?
cardiomyocytes do not contract as efficiently without taurine
Does taurine have any antioxidant function?
yes, important for the heart and eyes
Glutamine/Glutamate
[conditionally] essential AA; importnant in TCA, generating NADPH and GABA, and the antioxidant glutathione
GABA is a what?
neurotransmitter