Basic nutritional requirements Flashcards
1
Q
Digestion
A
Long chains of molecules are broken down into individual molecules
2
Q
Absorption
A
Those individual molecules can now be absorbed into the blood stream
3
Q
Metabolism
A
- Chemical reactions that occur within cells
- A lot of metabolic reactions happen in the liver
4
Q
Nutrient
A
Any food component that supports life
5
Q
Essential nutrient
A
a nutrient that cannot be synthesised by the body
6
Q
Types of macronutrients
A
- Water - most essential
- Protein
- Carbohydrates
- Fats/lipids
- Proteins, Carbs and lipids are responsible for all calories
- Macronutrients are needed in large quantities
7
Q
Types of micronutrients
A
- Vitamins
- Minerals
- Micronutrients are needed in tiny amounts
8
Q
Carbohydrates
A
- NOT essential in healthy adult cats and dogs - it can be synthesised by the body
- All animals have a metabolic requirement for glucose
- Carbs are broken down into a simple sugar e.g. glucose
- Provides energy source that’s metabolically efficient
- Carbs = water soluble
- Make up 60-90% of dry matter weight in food
- Polysaccharides e.g. fibre and starch are broken down into monosaccharides e.g. glucose and fructose, during digestion
- Glucose can be used for cellular respiration or stored as glycogen in the liver and skeletal muscles
- Enzymes hydrolyse the links between the sugars
9
Q
Fibre
A
- Polysaccharide
- Its structure makes it harder to break down then refined carbs like starch
- Made up of soluble fibre called pectin and insoluble fibre - mainly cellulose
Benefits of fibre:
- Promotes satiety (feeling full)
- Adds faecal bulk
- Increases amount of water that reaches large intestine
- Aids intestinal health via peristalsis
- They release fatty acids that provide nutrition to enterocytes (cells lining the gut)
- It releases sugar slowly, preventing blood glucose spikes
10
Q
Proteins
A
- Made up of amino acids
- Essential amino acids (EAA) - cannot be synthesised by body
- Non-essential = can be synthesised
- Liver produces new proteins
- Cells produce new proteins
- Amino acids are the building blocks of all proteins
- 20 different types of amino acid - some are essential nutrients
- Whether or not they are essential depends on the species
- 10 essential amino acids in dogs
- 11 essential amino acids in cats
11
Q
Protein metabolism - Deamination
A
- Bacteria in small intestine break down protein and as a by-product release ammonia
- The ammonia is transported to the liver by the hepatic portal vein
- The liver metabolises ammonia into urea (deamination)
- Urea is excreted by kidneys in urine
12
Q
Protein metabolism - transamination
A
- The liver also converts protein into usable amino acids
- This is transamination
13
Q
Protein metabolism - SUMMARY
A
- Excretion of waste from protein = Deamination (Detoxification of amino acids)
- Production of new proteins = Transamination (Transformation of amino acids)
14
Q
Protein deficiencies
A
- Reduced growth and repair rates
- Poor coat and skin conditions
15
Q
Protein excesses
A
- Weight gain
- Can exacerbate underlying pathologies relating to kidneys/liver
- Can exacerbate struvite crystal formation in animals predisposed
16
Q
Fats/lipids
A
- Good source of energy but metabolically inefficient
- Made up of glycerol and fatty acids
- Helps make food palatable
- Some fatty acids are essential nutrients - omega 3 and 6
- Needed for insulation, phospholipid bilayer, waterproofing fur, hormone production
- Most concentrated form of energy in the diet
- Is insoluble (hydrophobic)
- Triglycerides are used as energy or stored as adipose tissue
17
Q
Triglycerides
A
- Made up of glycerol and 3 fatty acids
- Each fatty acid is made up of a branch of hydrogen and carbon atoms
- The configuration of each strand of fatty acid falls into 3 different groups:
- Saturated
- Monosaturated
- Polysaturated
- Each category represents the amount of carbon double bonds in the molecule
18
Q
Essential fatty acids per species
A
Dogs = Linoleic acid (omega 6)
Cats = Linoleic acid (omega 6)
Non-essential:
Dogs = Arachindonic acid + Linolenic acid
Cats = Linolenic acid
19
Q
Functions of lipids
A
- Storage because insoluble in water
- High energy storage because yields more energy than carbs
- Production of metabolic water because it produces more water on oxidation than glycogen
- Thermal insulator because it’s a poor conductor
- Electrical insulator because it’s a poor conductor
- Waterproof because it’s a poor conductor
- Hormone production because it’s required to synthesise hormones
20
Q
Fat/lipid deficiencies
A
- Dry coat and scaly skin - making predisposed to pyoderma (skin infection)
- Impaired wound healing
- Severe deficiencies can result in emaciation and eventually death
21
Q
Fat/lipid excesses
A
- Obesity for fat deposition (adipose stores)
- Animals predisposed to pancreatitis would have the condition exacerbated by a high fat diet
22
Q
Vitamins
A
- Many vitamins function as co-enzymes
Co-enzymes are molecules that bind to the active site of enzymes
Types of water soluble vitamins include:
- C
- B1
- B5
- B6
- B9
- B12
- A - found in high levels in dietary liver. Important for eyesight
- D - Can by synthesised from UVB light. Essential for calcium absorption
- E - Important antioxidant
- K - Vital for coagulation (blood clotting)
- B and C - Both co-enzymes for metabolism and homeostasis
23
Q
Essential vitamins
A
- B - some synthesised in the gut
- A
- D - not enough synthesised through skin via UVB light
- E
24
Q
Non-essential vitamins
A
- C - except in guinea pigs and primates
- K - made by gut bacteria
25
Q
Antioxidants
A
- All cells carry out metabolic reactions
- Reactive oxygen species/ free radicals are a by-product of metabolic reactions
- Antioxidants neutralise free radicals
- There are many free radicals but the most important one is vitamin E
26
Q
Minerals
A
- Calcium - Ca
- Magnesium - MG
- Sodium - Na
- Phosphorus - P
- Chlorine - Cl
- Potassium - K
- Minerals are vital for homeostasis
27
Q
Electrolytes
A
- Calcium - Ca+
- Magnesium - Mg+
- Sodium - Na+
- Phosphate - PO-
- Chloride - Cl-
- Potassium - K+
- Electrolytes are minerals with an electrical charge
- They are metabolically active and are vital to homeostasis
- Found throughout the body and they’re maintained in fixed ranges within plasma
