Midterm 2 Flashcards
Nutrition
Interaction of food with the organism
Includes: prehension, eating, digesting, absorbing, metabolizing and eliminating
Essential nutrients
Things we have evolved to get from the environment
Amino acids
Fatty acids
Minerals
Vitamins
Minerals
Inorganic nutrients required in small quantities. Essential for high function. Sodium, calcium, potassium, copper and iodine
Sodium
Found in table salt. Too much increases bp. Nerves
Calcium
Found in dairy and dark green veggies. Bones and teeth
Potassium
Found in almost everything. Nerves
Copper
Vulcans and enzymes. Toxic in high levels
Iodine
Added to our salt because this part of the world is lacking it. Thyroid
Vitamins
Organic nutrients required in small quantities. Essential for normal function, can not be synthesized within the organism (other than vitamin D)
Which vitamins requires what mineral to function
Vit E and selenium
Water soluble vitamins
B’s and C’s
Fat soluble vitamins
ADEK
Where do we get C H and O
Directly from plants or if we eat animals who have eaten the plants
Macromolecules
Carbohydrates, lipids, proteins, nucleic acids
Carbohydrates
C, H and O. Most common is glucose. Glycogen is a big source of energy when lacking a meal
Storage polysaccharides
Where plants and animals store sugars
Starch= Plant storage (potatoes and grains)
Glycogen= Animal storage (muscle and liver)
Structural polysaccharides
Cellulose: cell walls in plants
Wood: Made of cellulose
Can be digested by fermentation, hard for monogastrics
Chintin: exoskeletons
Lipids
Glycerol + 3 fatty acids
Fate: Source of energy when readily oxidized
Unsaturated fatty acids: Double bonds, fewer hydrogens. Plants and fish fats. Omega 3= essential fatty acid for humans
Saturated fatty acids: Single bonds, saturated with hydrogen. Animal fats
Phospholipids
Major component of cell membrane in animals
Two fatty acids + glycerol + phosphate group
Steroids (lipids)
Carbon skeleton in rings. precursor for hormone synthesis
Proteins
Over 50% of dry matter in cells. Made up of amino acids (20). Long chains, folded structure. One amino acid change can cause sickle cell anemia (RBC’s do not form properly to carry enough oxygen)
Nucleic acids
In DNA and RNA. programs all proteins.
DNA
Purines: Adenine and guanine
Pyrimidines: Cytose and thymine
RNA
U=T (uracil)
Double helix
Caused by the AT GC bonds
How are macromolecules (fuel) delivered to the cells
Bloodstream
Glycolysis
No net ATP produced. pieces of glucose molecule get chopped off, glucose= 3 carbons= pyruvate. Changes nature of molecule. 34% efficient, rest is lost as heat. 30-32 ATP molecules will be produced
Pyruvate oxidation
Pyruvate turns into acetyl co-A. Needs O2 and B vitamins
Vitamin B
Shot can help when lacking energy to help speed up these reactions
Fermintation
If no oxygen is present after pyruvate oxidation, ethanol, lactate or other products are produced
NADH
Co- enzyme made from niacin (B3)
FADH
Contains riboflavin (B2)
Acetyl co-A
Co- enzyme made from pantothenic acid (B5)
Cellular respiration is driven by glucose
Directly from carbohydrates, indirectly from glycogen, fats (glycerol) and proteins (glucogenisis)
Proteins (amino acids), fatty acids and vitamins are required for intermediate compounds
Types of herbivores
Grazers and browsers
Grazers
Grasses and legumes (horses)
Browsers
Woody plants and grasses. Break down cellulose better (donkeys and deer)
Ingestion
Biting and chewing
- Harvesting food, grinding and mechanical breakdown
Salivation
- Adds water to food
- Adds enzymes (omnivores)
- Salivary amylaze: Glycogen and starch
Swallowing
- Moves bolus of food
Digestion (stomach)
Gastric juices and HCL + pepsin
HCl reduces pH and turns pepsinogen into pepsin (if we secreted pepsin, our body would digest itself
Digestive variants: Birds
Have gizzards. Replace teeth with grinding function
Ruminants: 3 compartments ahead of the stomach
Hindgut fermentors: Large cecum and large intestine
Ruminant compartments
1) Reticulum
2) Rumen
3) Omasum
4) Abomasum
Reticulum
Rumination gate keeper. Rumen bypass in calves
Rumen
Microbes are there to digest carbs. Materials can spend hours, days or weeks here. Microbes produce volatile fatty acids (energy)
Omasum
Absorbs water from rumen contents
Abomasum
Breaks down proteins. Like our stomachs without the strong acids
Coprophagy
Rabbits reinvest their wet feces to gain more nutrients, it breaks down further and is dry when eliminated the second time
Chief cells
Secrete pepsinogen
Pariteal cells
Secrete HCL
Gastric ulcer
When there is too much pepsin and it eats through the mucus
Why does stomach lining produce mucus
To protect itself
Which animals are hindgut fermentors
Horses, donkeys, elephants, rhinos, rabbits and koalas
Symbiotic digestion
Digesting cellulose
Large intestine
Fermentation: While water is present. VFA’s are absorbed for energy. High cellulose stuff (fiber) will be left over
Sucessful probiotics
Must be capsulated so they actually make it to the large intestine alive
Regulation of digestion
Mechanical: Full
Chemical: Blood glucose
Apetite: Mental
Gastric gland
Secretes substances made by the cells
Homeostasis
17-110mg of glucose per every 100mL of blood
How does the liver help achieve homeostasis
1) Can transport glucose into body cells and store as glycogen (when too high)
2) Can breakdown glycogen and release glucose into blood
How does the pancreas help achieve homeostasis
1) Secretes insulin when blood glucose level rises after eating (when too high)
2) Secretes glucagon (when too low)
What does glucagon do
Stimulates liver to convert glycogen to glucose
Volatile fatty acids
Acetate, propionate, butyrate
Acetate
Directed to muscles and fats
Propionate
Convert to glucose in the liver
Butyrate
Converted to ketone bodies
Each cellulose ring
Is a glucose
Cellulose
Complex carbohydrate that makes up plant cell walls
Very insoluble fibre in omnivore digestive system
What enzyme breaks down cellulose
Cellulase, found in microbes
Why do humans consume cellulose
To bulk up the diet, and to feel full, however humans tent to eat the low cellulose parts of plants
Process of rumination
Regurgitation. Develop symbiosis with organisms that can digest plant material
Dead microbes
Protein
Which VFA’s undergo the citric acid cycle
Acetic acid and butyric acid
Where do VFA’s in dairy cows end up
Milk fat (butter fat) or lactose (milk sugar)
Omnivores
Limited symbiosis with micrograms. High firer diet is no good
Appendix
Non functioning. Too much sitting in it and not moving causes appendicitis
Large intestine in omnivores
Not a great fermentor. Cellulose is not well broken down. Microbes can not be captured
Methods for omnivores when it comes to plants that are too high in fiber
Grains are the most digestible plant components
Processed plants (ground up)
Cooking: Can denature protein structure
Carnivores
Have to eat meat. Not enough enzymes in saliva to digest sugars
Produce glucose via glycogenesis and use normal cellular respiration from there on
Glycogenesis
Reverse glycolysis. All done in the liver. Costs energy. Starts with lactate in the muscles
Carnivore teeth
Large canines, lots of pre molars. Teeth overlap, mouths are full of bacteria.
Herbivore
Missing upper incisors, tiny canines ** Dental pad**
Grind food
Omnivores
Everything is pretty even
Crush food
Intracellular digestion
- In addition to exctra cellular digestion (small scale digestion)
- Circulating macromolecules. Substances are wrapped in vacuoles and digested in vacuole to avoid digesting the cell
When do horses need their teeth done
When they drool while eating and when there are whole kernels of corn/ grain in stool
What are volatile fatty acids
- Produced by microbes
- Can be absorbed by cecum or large intestine to produce energy. Excess VFA’s go directly to tissues
- Can’t capture microbial protein via stomach and small intestine because the cecum is behind that
Toxic plants for equids
Jugulone (nut trees): Toxicosis (colic, swelling, laminitis)
Oak, red maple: Acorns, wilted leaves
Cherry plumb
Cyanide compounds in leaves, pits
