nutrition and digestion

____ are heterotrophs

animals

what are heterotrophs

they derive their nutrition from eating other organisms

____ are autotrophs

plants, some bacteria, some archaea, and some protists

what are autotrophs

they can use solar energy or inorganic chemical energy to synthesize all of their nutritional needs

what is a calorie

a unit of heat energy which described the amount of heat necessary to raise the temperature of 1 gram of water 1 degree celsius

what is a Calorie

1 Cal = 1000 calories

why is energy conversion inefficient

a large portion of the original energy always ends up as heat.

what are macronutrients

macronutrients are the components of food that provide energy

what are the macronutrients of food

fat, carbohydrates, and proteins

how much energy does fat yield in terms of Calorie

9.5 Cal/gram

how much energy does carbohydrates yield in terms of Cal

4.2 Cal / gram

how much energy does protein yield in terms of Cal

4.1 Cal / gram

where are carbohydrates stored

in the liver and in muscle cells as glycogen

limitations of storing glycogen for energy

the total glycogen stored only last for a day’s basal energy requirement

why is fat good at storing energy

fat has more energy per gram than glycogen, it can be stored with little associated water, making it more compact and less expensive to carry

what happens when an animal eats more food than its energy requirements

the excess nutrients are stored as increased body mass

first glycogen reserves build up, then additional dietary carbohydrates, fats ,and proteins are converted to body fat

what do animals use the acetyl group for

serves as building blocks, supplying the carbon skeleton of larger organic molecules

where do animals get acetyl groups from

animals cannot synthesize acetyl groups and must obtain them from food. Acetyl groups can be derived from almost any food, but they originate in plants

how can animals synthesize their own amino acids

animals can synthesize some of their own amino acids by using carbon skeleton from the acetyl group and transferring them to amine group (-NH2)

essential amino acids

amino acids that cannot be synthesized and must be obtained through food

what are the eight essential amino acids for adult humans

• isoleucine

• leucine

• lysine

• methionine

• phenylalanine

• threonine

• tryptophan

• valine

why are dietary proteins digested to their constituent amino acids before it can be used by the body

• macromolecules( proteins) are not readily absorbed by the cells of the gut, but amino acid are readily absorbed

• a protein’s function is more species-dependent

• foreign proteins pose the risk of being mistaken as invaders by the immune system

what are the two essential fatty acids a human needs

• linoleic acid

• alpha-linolenic acid

uses of linoleic acid

is needed by mammals to synthesize other unsaturated fatty acids

mineral macronutrients

elements required in large amounts

mineral micronutrients

elements required in only tiny amounts

what are the mineral macronutrients

• calcium

• chlorine

• magnesium

• phosphorus

• potassium

• sodium

• sulfur

sources of calcium

dairy, eggs, leafy veg, whole grains, legumes, nuts, meat

sources of chlorine

table salt, meat, eggs, veg, dairy

sources of magnesium

green veg, meat, whole grains, nuts, milk, legumes

sources of phosphorus

dairy, eggs, meat, whole grains, legumes, nuts

sources of potassium

table salt, dairy, meat, eggs

sources of sulfur

meat, eggs, dairy, nuts, legumes

function of calcium

found in bones and teeth; blood clotting; nerve and muscle action; enzyme activation

functions of chlorine

water balance, digestion (as HCl); principal negative ion in extracellular fluid

functions of magnesium

required by many enzymes, found in bones and teeth

functions of phosphorus

component of nucleic acids, ATP and phospholipids, bone formation, buffers, metabolism of sugar

functions of potassium

nerve and muscle action, protein synthesis, principal positive ion in cells

functions of sodium

nerve and muscle action, water balance, principle positive ion in extracellular fluid

functions of sulfur

found in proteins and coenzymes, detoxification of harmful substances

why is the turnover of calcium in the extracellular fluid high

bones are constantly being remodeled and calcium is constantly entering and leaving cells. calcium leaves the body in urine, sweat, and feces - must be replaced regularly.

what are vitamins

carbon compounds that an animal requires for growth and metabolism but cannot synthesize for itself

what are the two groups of vitamins called

• water-soluable

• fat - soluble

what are water soluble vitamins

when water soluble vitamins are ingested they get dissolved by water and eliminated in the urine.

they require daily intake

what are fat soluble vitamins

vitamins are ingested and are stored in fat tissues and liver for long term use. However as they accumulate, they may build up to toxic levels in the liver if taken in excess

function of B1 vitamin

coenzyme in cellular respiration

deficiency of B1 symptoms

beriberi(severe lack of B1), loss of appetite, fatigue

function of B2 vitamin

coenzyme in FAD

deficiency symptoms of a lack of B2

lesions in corners of mouth, eye irritation, skin disorders

function of B3 vitamin

coenzyme in NAD and NADP

deficiency symptoms from a lack of B3

pellagra, skin disorders, diarrhea, mental disorders

function of B5 vitamin

found in acetyl CoA

deficiency symptoms from a lack of B5

adrenal problems, reproductive problems

function of B6 vitamin

coenzyme in amino acid metabolism

deficiency symptoms from a lack of B6

anemia, slow growth, skin problems, convulsions

function of B7 vitamin

found in coenzymes

deficiency symptoms from a lack of B7

skin problems, loss of hair

function of B12 vitamin

formation of nucleic acids, proteins, and red blood cells

deficiency symptoms from a lack of B12

pernicious anemia

function of folic acid vitamin

coenzyme in formation of heme and nucleotides

deficiency symptoms from a lack of folic acid

anemia

function of vitamin C

formation of connective tissues; antioxidant

deficiency symptoms from a lack of vitamin C

scurvy, slow healing, poor bone growth

name all the water-soluble vitamins

• B1 (thiamin)

• B2 (riboflavin)

• B3(niacin)

• B5 (pantothenic)

• B6(pyridoxine)

• B7 (biotin)

• B12 (cobalamin)

• folic acid

• C (ascorbic acid)

name all the fat - soluble vitamins

• A (retinol)

• D (calciferol)

• E (tocopherol)

• K (menadione)

function of vitamin A

found in visual pigments

deficiency symptoms from a lack of vitamin A

night blindness

function of vitamin D

absorption of calcium and phosphate

deficiency symptoms from a lack of vitamin D

rickets

function of vitamin E

muscle maintenance, antioxidant

deficiency symptoms from a lack of vitamin E

anemia

function of vitamin K

blood clotting

deficiency symptoms from a lack of vitamin K

blood clotting problems

malnutrition

the lack of an essential nutrient in the diet

results of a deficiency disease

a deficiency disease prevents the body from taking in essential vitamins, minerals, and macronutrients

Damaged intestines, digestive enzyme shortages, or lack of intrinsic factor (for B12) prevent nutrient transfer into the bloodstream, leading to chronic symptoms like anemia, weakened immunity, and bone damage

how does self consumption happen

the body will metabolize some of the molecules of its own body if too little food. when fat reserves are depleated, the body will sacrifice proteins - blood plasma

what happens when the body digests blood plasma via self consumption

the loss of plasma proteins decrease the osmotic concentration of the plasma, resulting in increased loss of fluid from the blood to the interstital spaces. accumulation of the fluid here is called kwashiorkor - chronic protein deficiency.

what is pernicious anemia

an autoimmune condition where the body destroys stomach cells that produce intrinsic factor, a protein necessary for absorbing vitamin B12

what are saprobes

organisms that absorb nutrients from dead organic matter

what types of animals are usually saprobes

protists or fungi

what are detritivores

decomposers - organisms that eat dead organic material

what types of organisms are detritivores

earthworms and crabs

what are predators

animals that feed on living organisms

what are herbivores

animals that eat plants

what are carnivores

animals that eat other animals

what are omnivores

animals that eat both plants and animals

what are filter feeders

animals that prey on small organisms by filtering from the aquatic environment

what are the three layers of a vertebrate’s teeth

• an extremely hard material, enamel, covers the crown of the tooth

• the crown and root contain dentine

• inside, the pup cavity contains blood vessels, nerves, and dentine producing cells

function of incisors

used for cutting, chopping, and gnawing

function of canine teeth

used for stabbing, gripping, and ripping

function of molars and premolar teeth

used for shearing, crushing, and grinding

overview of how digestion works

when an animal eats food, that food is brought to a body cavity where they secrete digestive enzymes into, and the enzymes break down the food into nutrient molecules which can be absorbed by the cells lining the cavity

what is a gastrovascular cavity

a specialized digestive system which connects to the outside world through a single opening

what animals use a gastrovascular cavity and how does it work

cndarians, like jellyfish will capture its prey then cram it into its mouth which links directly to the cavity. enzymes in the cavity will digest the prey

what is a gastrointestinal system

animals with bilateral symmetry have a tubular digestive system called a gastrointestinal system of simply gut

what happens in the gut

food is moved through the gut as it is sequentially disassembled/ digested and the smallest units of the digest food are absorbed across the gut wall

what happens to solid wastes

solid digestive wastes are eliminated through an anus

what are stomachs and crops

a storage chamber that enables animals to ingest relatively large amounts of food when it is available, and then digest it gradually.

where does food go after it leaves the stomach

food is delivered into the next section of the gut, the intestine

what is the food like as it enters the intestines

the food is in small particles, well mixed, and usually partially digested