L2 - macronutrients

Characteristics of a wild animal

• undomesticated

• not living under human control

• untamed

Characteristics of a domesticated animal

• direct ancestors have undergone a domestication process

• managed by humans

Domestication

Evolutionary process during which humans establish control over:

• Living space

• Care and welfare

• Selection of mating partners

• Reproduction

• Diet

*throughout domestication, the species is genetically altered from its wild ancestral form

Tame animal

• An animal that has been familiarized with humans → tractable (easy to control/influence)

• Can apply to ‘wild’ or ‘domesticated’ animals

Feral animal

An animal that lives in the wild state, but whose ancestors have undergone a domestication process (e.g. feral cats)

Nutrition

The process whereby an animal obtains and utilizes portions of its external environment (food) for the continued functioning of its metabolism

Define nutrients

Organic and inorganic chemical compounds used by an animal to support maintenance, growth, and reproduction

6 Categories of nutrients:

1. water

2. carbohydrates

3. proteins

4. lipids

5. vitamins

6. minerals

Energy yielding nutrients include:

• carbohydrates (monosaccharides)

• proteins (amino acids)

• lipids (fatty acids)

Organic vs inorganic

Organic nutrients contain carbon in their structure (C-C or C-H), inorganic nutrients do not

Examples of free water:

• drinking water

• ponds

• rivers

• lakes

• puddles

Examples of dietary water

Water contained in food:

• fresh grasses ~75% water

• lean tissue/meat ~70% water

• other foods variable

(e.g. seeds ~10% water vs fruits ~70-90%)

Metabolic Water

• Produced during oxidation of energy-yielding nutrients

• Oxidation results in the production of water, CO2, and energy (ATP)

• creating form digesting food

Monosaccharides characteristics and types

• single sugar building blocks of carbohydrates

• Pentoses (e.g. ribose) = 5 carbon

• Hexoses (e.g. glucose, fructose, galactose) = 6 carbon

• Absorbable units

Disaccharides characteristics and types

• two monosaccharides joined by a glycosidic bond

• Sucrose = glucose + fructose

• Lactose = glucose + galactose

• Maltose = glucose + glu

  cose

Oligosaccharides

3-10 monosaccharide chain (short-chain)

Polysaccharides

• 10+ monosaccharide chain (long-chain)

• most abundant carb found in food

Types of polysaccharides

Plant-based polysaccharides

• starch (energy storage, long term)

• cellulose, hemi-cellulose, lignin (cell wall structural components)

Animal-based polysaccharides

• glycogen (energy storage, short term)

• chitin (structural component)

Chitin

long chain polysaccharide made of N-acetylglucosamine, a derivative of glucose

Amino acid characteristics

• building blocks of protein

• 20 standard, genetically coded, proteinogenic amino acids

• Absorbable units

Peptide

two or more amino acids joined by a peptide bond

Dipeptide

pair of amino acids linked by a peptide bond (absorbable unit)

Polypeptide chain

long, unbranched peptide chain

Amino acids are required for:

• Building and maintaining tissue (e.g. muscle, bone, skin, hair, hooves, feathers)

• Synthesizing enzymes

• Synthesizing blood constituents (e.g. heme precursor = glycine)

• Synthesizing hormones

• Synthesizing secondary metabolites (e.g. serotonin precursor = tryptophan)

• Yielding energy

Amino Acid structure

How does peptide formation occur

• Reaction between the carboxyl group of one a.a. and the amino group of another a.a.

• Forms a peptide bond and results in formation of 1 molecule of water (H2O)

Essential amino acids

Can’t be made at all by the animal (or by microorganism within the animal) or can’t be made in sufficient enough quantities to meet requirements so these nutrients must be present in sufficient quantities in the diet

Types of essential amino acids

Conditionally essential amino acids

building blocks of protein that the body normally makes on its own, but which become necessary from the diet during times of illness, severe stress, rapid growth, or trauma

Types of conditionally essentially amino acids

• Phenylalanine → Tyrosine

• Methionine → Cysteine → Taurine*

*Essential for all felids

• Arginine

Types of Proteinogenic Amino Acids

Glucogenic amino acids

a building block of protein that the body can turn into glucose through a process called gluconeogenesis

Ketogenic amino acids

building blocks of proteins that break down into acetyl-CoA or acetoacetyl-CoA, which the body uses to make ketone bodies or fatty acids, rather than glucose

Types of lipids

• Fatty acids (Absorbable unit)

• Fatty acid derivatives; Monoglycerides (Absorbable unit), Diglycerides, Triglycerides (Fats), Phospholipids

• Waxes

• Sterols (e.g. cholesterol)

General FA structure

• Carboxyl group at one end (COOH)

• Linear hydrocarbon chain (compound of H and C); most FAs have an even number of carbons (saturated)

• Methyl group at the other end (CH3)

FA nomenclature depends on:

• Hydrocarbon chain length

• Degree of saturation (number of double bonds)

• Position of double bonds in the chain

• Orientation of hydrogen atoms around double bonds (cis or trans)

FA nomenclature:

A:BnC

• A = number of C atoms (hydrocarbon chain length)

• B = number of double bonds (degree of saturation)

• C = Position of the 1st double bond relative to the omega C (methyl group C)

FA factors that influence melting point

Increase MP:

• carbon chain length

• odd numbered chain

Decrease MP:

• double bonds

• cis-double bonds

How are fats stored as

Triglycerides (TAG): 3 fatty acids + 1 glycerol

Phospholipid structure

How are FAs synthesized

• most mammals can sufficiently synthesize saturated FAs

• synthesized in adipocytes of ruminants and in liver of non-ruminants

How are PUFAs formed

• most mammals can elongate and desaturate fatty acids to form PUFAs

• elongate = add 2 carbons at a time to the chain

• desaturate = add double bond to chain

Essential FAs of mammals

Most mammals require in the diet...

1. Linoleic acid (18:2n6) → plant based

2. Alpha-linolenic acid (18:3n3) → plant based

3. Arachidonic acid (20:4n6) → animal based *Only for strict carnivores (e.g. felids)