Animals - Chapter 9

Question 1

Nutrients

Answer 1

all organisms must have a way of obtaining essential nutrients
essential nutrients = basic/raw materials needed to provide energy, regulate cellular activities, and to build and repair tissues

Question 2

Macromolecules

Answer 2

these are the essential nutrients that our bodies need
they are larger, more complex assemblies of organic molecules which contain carbon bonded to hydrogen, as well as other atoms
CHON, SP (carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus)

Question 3

Carbohydrates

Answer 3

1 carbon : 2 hydrogens : 1 oxygen
function = short term energy storage, main source of energy, structure (cell walls and exoskeleton)
monomer = monosaccharides (glucose, fructose, galactose)
examples = disaccharides (sucrose, lactose, maltose), polysaccharides (glycogen, chitin, cellulose)
energy content = 37 kJ/g

Question 4

Lipids

Answer 4

1 carbon : 2 hydrogens : very few oxygens
function = long term energy storage, insulation, protection and cushioning of organs, cell membranes, hormones
monomer = triglycerides (glycerol, fatty acid chains)
examples = fats, phospholipids, steroids
energy content = 17 kJ/g

Question 5

Proteins

Answer 5

elements = CHONS (no ratio)
function = structural molecules, metabolic activities, motion, hormones, can be converted to high-energy storage molecules
monomer = amino acids
examples = enzymes, nails, hair
energy content = 17 kJ/g

Question 6

Nucleic acids

Answer 6

elements = CHONP (no ratio)
function = genetic code, heredity, cellular energy molecules
monomer = nucleotide
examples = DNA, RNA, ATP

Question 7

Water

Answer 7

needed for the proper functioning of all cells and organs, ⅔ of the body mass
functions include =
transporting dissolved nutrients into the cells that line the small intestine
flushing toxins from cells
lubricating tissues and joints
forming essential body fluids, such as blood and mucus
regulating body temperatures
eliminating waste materials

Question 8

Vitamins

Answer 8

organic molecules the body needs in small quantities
regulate cell functions, growth, and development
some are fat soluble (ADEK) some are water soluble (BC), which impacts on how they are processed and eliminated

Question 9

Minerals

Answer 9

elements the body needs in small quantities

aid in metabolic processes and in tissue building/repair

Question 10

Metabolism

Answer 10

chemical reactions that the body performs in order to stay alive
catabolism = the breakdown of materials (digestion)
anabolism = the building of larger molecules (growth and repair)
metabolic rate = rate of converting stored energy into working energy, varies with body size, physical activity level, sex, age, hereditary factors
basal metabolic rate = minimum amount of energy required to keep you alive

Question 11

Types of digestion

Answer 11

intracellular digestion = digestion inside the cell, occurs through phagocytosis (cell engulfs the food)
examples = single-celled organisms
extracellular digestion = digestion outside the cells, food enters a tube and exits from another end
examples = most animals, human digestive tract

Question 12

Mechanical digestion

Answer 12

the physical breakdown of large food particles into smaller ones
achieved through chewing, mashing, chopping
this increases the surface area of the food, allowing more enzymes to come into contact with the food

Question 13

Chemical digestion

Answer 13

the chemical breakdown of large molecules into smaller ones
macromolecules are broken down into their monomers
food particles are broken down by enzymes, each enzyme has a pH at which it performs best

Question 14

Filter feeders

Answer 14

use a body structure that is similar to a filter basket

siphons water into its mouth and then filters it to obtain small organisms

Question 15

Fluid feeders

Answer 15

suck or lick fluids from live plants or animals

mouth parts are adapted to pierce or rip skin or tear tissue

Question 16

Substrate feeders

Answer 16

live in or on their food source and eat their way through it

Question 17

Bulk feeders

Answer 17

includes many animals, and most vertebrates

ingest fairly large pieces of food

Question 18

Types of digestive systems

Answer 18

incomplete = one opening, nutrients absorbed by lining of the cells, digestion continues inside the cells
complete = 2 openings, one for intake one for waste, organized into specialized regions that enable breakdown and absorption, one way flow
complete digestive system allows an organism to continuously feed and have more efficient digestion

Question 19

Stages of the digestive system

Answer 19

there are four stages to food processing
ingestion = taking in food
digestion = breaking down food into nutrients
absorption = taking in nutrients by cells
egestion = removing any leftover wastes

Question 20

Egestion

Answer 20

fiber is made up of cellulose which cannot be digested by humans
it provides the bulk in the colon
bulk pushes against inner walls of colon to stimulate egestion

Question 21

Gastrin

Answer 21

secreted from the stomach
stimulates the release of gastric juices into the stomach (pepsin, HCl) in order to help with digestion and protection of the stomach

Question 22

CCK

Answer 22

secreted from the duodenum
signals the pancreas to secrete a variety of substances to control the pH of the intestine, and enzymes that are needed for digestion
signals stomach to slow down speed of digestion or small intestine can digest fats

Question 23

Secretin

Answer 23

secreted from the duodenum
stimulates liver to make more bile
encourages pancreas to secrete lipid and protein enzymes, and bicarbonate ions to neutralize chyme

Question 24

Insulin

Answer 24

secreted from the pancreas

binds to special receptors on cells and allows glucose the enter the cells through the membrane

Question 25

Glucagon

Answer 25

secreted from the pancreas

stimulates the liver, muscle cells and fat cells to break down glycogen and release glucose into the bloodstream

Question 26

Enzymes

Answer 26

molecules that speed up the rate of reaction
are usually protein based and therefore quite specific to a substrate
can function only at an optimal temperature and pH level

Question 27

Carbohydrate digestion

Answer 27

begins with the action of the enzyme amylase in the mouth, which breaks the starch down into disaccharides
restarts in the duodenum with pancreatic amylase, which breaks down the disaccharides into monosaccharides (glucose rings)
in the small intestine, maltase breaks down maltose (disaccharide) into two glucose molecules

Question 28

Protein digestion

Answer 28

HCl is released in the stomach and converts pepsinogen into its active form of pepsin, which breaks down proteins into shorter polypeptides
the pancreas secretes inactive trypsinogen which converts to active trypsin in the small intestine and breaks down any partially digested molecules that remain
the small intestine secretes erepsin which then digests the peptones into amino acids

Question 29

Lipid digestion

Answer 29

occurs only in the small intestine
bile, secreted from the liver, emulsifies fats, breaking them down into micelles in order to increase their surface area
pancreatic lipase then breaks down the lipid chains into individual molecules (glycerol and fatty acid chains)

Question 30

Passive transport

Answer 30

transport of materials (solutes, molecules, ions) that does not require extra energy from the cell

Question 31

Diffusion

Answer 31

tendency of particles to spread out from an area of high concentration to an area of low concentration across a permeable membrane
difference in concentrations is the concentration gradient
molecules diffuse until the point of equilibrium has been reached, and there is no more concentration gradient
osmosis = diffusion of water across a selectively permeable membrane

Question 32

Facilitated diffusion

Answer 32

the diffusion of particles across a selectively permeable membrane by way of a protein channel
molecules are still moving down the concentration gradient but are using the protein to provide a channel from one side of the membrane to the other
often larger or charged molecules are transported this way

Question 33

Active transport

Answer 33

process whereby a solute is moved against the concentration gradient (Iow to high concentration)
due to concentration gradient, the cell must expend energy to work the pump that is moving the molecule
energy used by the cell is ATP