ANS 230 Exam 1

What is nutrition?

Choices we make about food that affect individual cells to the environment

Sum of processes by which an animal takes in a utilities food

Science that interprets interaction of nutrients that affects different physiological stages

Why does nutrition matter

Biological reasons: Need to know nutrient requirements for health

Management: Feed and feeding strategies

Economic: Feed costs and ROI

-Feed is the largest variable cost in animal production

How much of operating budget is feed costs

More than 70%

What does nutrition directly influence

Productivity, efficiency, and profitability

What does feed efficiency measure

How much of nutrient is being retained by animal and how much is wasted/excreted

What does small changes in feed efficiency scale to

Billions of dollars

Size of agriculture GDP

Share is small but societal impact is large

More efficient=

less waste

How does agriculture reduce poverty

Reduces poverty more effectively than any other sector

Ag growth is 2-4 x more effective in raising income than other sectors

What are animals related to plant energy? Why?

Biochemical converters of plant-derived nutrients

Animals cannot synthesize energy

Only source of energy/glucose

Plants

Only sustainable reaction

Photosynthesis

Photosynthesis formula

What disciplines does nutrition use

Biology: enzymes, tissues, regulation

Chemistry: bonds, re-dox

Physics: energy transfer, heat loss

What is catabolic and anabolic? Do they require energy? Transform what to what

Catabolic: breaking down molecules

Releases energy (exergonic)

glucose → ATP

Anabolic: reassembling molecules

Requires energy (endergonic)
amino acids → muscle protein

What is metabolism

Interconversion of nutrients to supply energy

Major source of inefficiency

Heat loss

Define 5 major nutrition processes

Ingestion: feed intake

Digestion/Absorption: breakdown and uptake

Metabolism: chemical transformations

Assimilation: use for structure/functions

Excretion: waste removal

What factors can we not control

Feed intake

Don’t know if they will eat the diet

What is energy not

Energy is not a nutrient!

It is an entity within a nutrient

How is energy measured

ATP

What is redox potential? Reduction vs oxidation? Measured in what?

Tendency of chemicals (nutrients) to gain/lose electrons

Reduced: gain electrons

Oxidized: lose electrons

Measured in volts (V) or millivolts (mV)

ATP generation depends on what

Controlled oxidation of nutrients

Who is Antoine Lavoisier

Father of nutrition and chemistry

Established link between respiration, oxidation, and energy metabolism

Founder of calorimetry and energy systems

What are the principles of nutrition

Physiology differs but energy laws do not

First law of thermodynamics

Energy/mass can not be created or destroyed, it is always conserved

Energy out=energy in but it can change form

Intake formula

Intake = retained-lost

Retained: milk, eggs, meat

Lost: feces, urine, methane

3 principles of nutrition

Balance: correct portions

Quality: nutrient composition

Bioavailability: usable fraction

What factors affect nutrient use by animals

Intake: palatability, access

Gut environment: microbiome, pH

Digestion and absorption: enzymes, transit time

Why do chemistry matter in biology

All biological processes driven by chemical interactions

Biologically important molecules?

Glucose, amino acids, fatty acids

What determines function at molecular level

Structure

Structural organizational pyramid

Smallest independently functional unit of body

Cell

Where is energy? In what bond?

Carbon bonds

Sometimes hydrogen

Prokaryotic vs eukaryotic cells

Prokaryotic cell: simple, no membrane-bound nucleus or organelles, unicellular

-Bacteria

-Archaea

Eukaryotic cell: complex, membrane-bound nucleus and specialized organelles

-Animals

-Plants

-Fungi

-Protists

Size of animal and bacterial cell

Bacteria: 0.5 - 5 µm in diameter

Animal: 10 - 100 µm in diameter

Animal cell is 10-20 times larger and 1000 times greater volume

Bacteria cell=marble Animal cell=grapefruit or tennis ball

What are the six nutrients

1) Carbohydrates: CHO, energy (glucose, starch)

2) Proteins: AA, energy, enzymes, structure, signaling

3) Lipids: energy (long term), membranes, insulation

4) Water: temp regulation, solvent for rxs

5) Minerals: structural (Ca, P) vs regulatory (Na, K)

6) Vitamins: cofactors in metabolism

What nutrients for energy

Carbs and lipids

Protein goes into energetic pathway but shouldn’t be included to meet energy requirements

Nutrients may be what

Source of energy (carbs, proteins, lipids)

Macro vs micro (how much of nutrient is required)

Organic or inorganic (minerals and H2O because lack C)

What is a dispensable nutrient

Not needed in diet because is made by animal

Still essential

What is a indispensable nutrient

Must be provided because cannot be made by animals

Conditionally indispensable means it can’t be made by animal in sufficient quantities

What are some species specific indispensable amino acids

Taurine: indispensable for cats due to limited synthesis

Arginine: conditionally indispensable during severe illness, trauma, or genetic conditions like sickle cell anemia

Glutamine: needed in higher amounts during stress (surgery, burns) for gut health and immune function

What are some species specific indispensable vitamins and minerals

Vitamin C: guinea pigs and primates can’t make it

B vitamins (B12): microbes produce most B vitamins (only microbes make B12); rabbits practice coprophagy to re-ingest nutrients

Factors that influence conditionally indispensable nutrients

Growth and life stage: neonates often need nutrients (arginine, glutamine, choline) that adults can make

Disease/stress: trauma, infection, or metabolic disorders overwhelm synthesis pathways (arginine, glutamine in sepsis)

Dietary imbalance: poor quality protein or lack of precursors

Animal vs plant cells

Animal vs plant cell: energy

Plants: autotrophic using chloroplasts for photosynthesis which turns sunlight into glucose

Animals: heterotrophic using mitochondria for cellular respiration (glucose to ATP)

Animal vs plant cell: structural support

Plants: rigid cell wall made of cellulose provides shape and protection and prevents bursting in water

Animals: flexible cell membrane phospholipid bilayer only (no cell wall) which allows movement, shape changes, and immune functions

Animal vs plant cell: water and waste management

Plants: large central vacuole maintains turgor pressure (firmness) and stores water/nutrients/waste

Animals: multiple small vacuoles/vesicles that rely on lysosomes for waste breakdown

Animal vs plant cell: communication

Plants: plasmodesmata (channels through cell walls) for cell to cell communication

Animals: gap junctions allowing flexibility in tissue structure (muscle, nerves)

Animal vs plant cell: energy storage

Plants: store energy as starch

Animals: store energy as glycogen (glucose) or triglycerides (excess glucose)

What do plant and animal cell have in common

Eukaryotes with cell nucleus that houses chromosomes

How do place synthesize amino acids

From inorganic N (reduces nitrates in soil)

Legumes can fix atmospheric nitrogen to make amino acids

What percent of air we breathe is nitrogen

70%

What is energy

Property of systems (not a substance)

Capacity to do work - physical, chemical, or biological

Key principles of energy

It can be transferred (heat, work, radiation)

It can be transformed

Total energy is conserved (1st law of thermodynamics)

What drives all reactions in body

ATP

What do all reactions release

Heat

What is the 2nd law of thermodynamics

In any energy transfer the entropy (disorder) increases

-Not 100% efficient

-Chemical reactions release heat, heat is dissipated from the body

Metabolism efficiency related to generation of heat

How is energy measured in animals

By their metabolic rate

What is metabolic rate? What units is it usually expressed in? How is it calculated? Direct vs indirect calorimetry

Amount of energy an animals uses over a specific time

Calories (kcal) per unit time - joules in other countries

Calculated by measuring O2 consumed and CO2 produced (indirect calorimetry)

-Direct measures heat produced from animal

C vs c

C: kilocalories = 1000 calories

c: calories

What does basal metabolic rate stand for

Maintenance

Energy expenditure 3 main categories most to least

1) Resting metabolism (maintenance) - 60%

2) Physical activity

3) Thermic effect: energy required for digestion, absorption, and nutrient processing

How can basal metabolic rate be broken down

Per Animal (Whole-Body BMR)

-Total energy expenditure (24 hr)

-kcal/day

-Useful to determine energy required

Per Unit of BW (Mass-Specific BMR)
gg

-BMR relative to animal’s BW

-kcal/kg BW/d

Per Unit of Metabolic BW (BW ^0.75)

-Most accurate to compare different species (accounts for surface area and volume ratios)

-kcal/kg BW ^0.75/d

What is each BMR method used for

Does elephant or mouse have higher BMR

Per Animal: elephant

Per Unit of BW: mouse

Why do smaller animals have higher BMR

Small animal have lower mass=higher BMR b/c larger surface area to volume loses heat faster so more energy is needed to maintain internal temp

-Takes a lot of time for heat to leave the animal if they are larger

Heat lost through surface area (skin)

Heat is generated in volume (body tissues)

Small animals have more surface area per unit of body mass so they lose heat and burn energy faster → higher BMR per gram of body mass

What is BMR also referred to as

Fasting catabolism

-Body breaks down its own tissue reserves, no external energy provided

-Energy expanded in fasting animal

-Estimated by heat production measured by direct or indirect calorimetry in respiration chamber

Conditions needed to assess BMR

Animal must be awake

Complete physical and mental rest

Post absorptive state - not actively digesting food (fasting)

Thermoneutral environment

How do endotherms use heat that comes from byproduct of metabolism

Use metabolic heat to maintain stable internal body temp

BMR defintion

Baseline rate of energy used in a resting, fasting animal at neutral temps

What happens to metabolic rate with activity

Increases - more active animals burn more energy

What is torpor

When animals can dramatically lower their metabolism

Hibernation: winter torpor

Estivation: summer torpor

Which animal has highest metabolic rate

Hummingbird

Goes into torpor every night to lower metabolism

How to calculate metabolic body weight

Body weight to the power of 0.75

BMR chart

Metabolic body weight BMR numbers are so close together so good for comparing species

What can help slow aging

Environment:

Colder temperatures → slower heartbeats and metabolic rates

Antarctic glass sponge: 10,000 years

Size:

Larger animals almost always live longer than smaller ones

Some small animals made up of cells that can’t divide and be replaced when damaged so their bodies expire more quickly

Smaller animals prone to predators so reproduce more quickly and in greater numbers

Exceptions: bats, birds, turtles

Genetic differences:

How an organism’s cells respond to threats

Animal with slowest metabolism? What do they eat? How do that combat this with body feature? How long to process meal? Bathroom? How much less muscle mass than animals their size? Body temp

3-toed sloths

Rely on leaves exclusively and they are hard to digest and absorb energy from

To combat this they have a multi-chambered stomach that takes up 1/3 of their body

Can spend 1-3 weeks processing a meal

Don’t move much - descend once a week for bathroom

30% less muscle mass than animals their size

Body temp can fluctuate more than most mammals

Energy formula in animals

Reverse of that in plants

Carbs in plant and animal cells

Plants: sugars and starch (cell contents)

Plants: cellulose/hemicellulose (cell wall)

Animals: carbs (CHO) = major energy source

Carbohydrates empirical formula

Cm (H2O)n

How much of plant matter is carbs

60-90% of plant dry matter

How much energy in cellulose

80% of energy on planet in cellulose

How do we classify carbohydrates

Monomer type — Chemical identity

Degree of polymerization (DP) — Size and solubility

Linkage type (α vs β) - geometry of bond — Strength and digestibility

Discuss monomer type

Homo-polysaccharide: made of the same sugar units (monomers), usually glucose

Hetero-polysaccharide: made of different kinds of polysaccharides

Discuss Degree of polymerization (DP)

How long is the molecule

Oligo: 3-10 units

Poly: several units
Linear or branched

Discuss Linkage type (α vs β) - geometry of bond

Most critical for digestibility

α linkages: starch - easier to digest

-Both hydroxyl groups (OH) point on the linking carbons point in same direction

-Bond forms straight or parallel linkage across same plane

-Starch and glycogen - easily broken down

β linkages: cellulose

-Hydroxyl groups are on opposite sides of plane from each other

-Bond connects diagonally across plane

-Cellulose

Chemically identical but structurally different

Alpha vs beta glucose

Alpha: both hydroxyls pointing down

Beta: hydroxyls pointing opposite directions

Do pigs and cows eat starch or cellulose

Pigs: starch

Cows: cellulose - microbes to break it down, in majority of forages

How many carbons in glucose

6

Major dietary carbs table

What is soluble fiber

Instead of plant cell (starch and protein) - doesn’t include cell wall made of cellulose and hemicellulose

Structural vs nonstructural polysaccharides

Structural: cell wall so cellulose and hemicellulose

Nonstructural: inside cell so starch and protein

What are monosaccharides? Is it water soluble? Two common types?

Smallest carbs (> or = 3 C)

Highly water soluble

Glucose, galactose

Arabinose, xylose

What are 5 and 6 carbon molecules called

5: Pentoses

6: Hexoses

What are these molecules

Glucose

Fructose

Galactose

All monomers and single molecules

Where is glucose, fructose, and galactose found? Why does it matter

3 functional groups you need to know

Carbonyl bond on inside = ketose sugar

Carbonyl bond on terminal end = aldose sugar

What is ketosis

When body switches from burning carbs to burning fat

Breaks down fatty acids (liver bodies) for energy

Too many or too few ketone bodies indicate issues with metabolism