Test 1 Human Bio

Everything up to Test 1

science of biology

the study of living organisms and the environment they live in

cell

smallest structural and functional unit of an organism

tissue

group of similar cells that perform a particular function

organ 

composed of several tissue types 

organ system

group of organs that work together to form a common purpose

organism

a collection of organ systems

species

a group of interbreeding organisms

population

the members of one species in a particular area at a particular time

community

interacting populations

ecosystem 

community of populations interacting with the physical environment

biosphere

includes all of the places on the earth where living organisms exist

energy

the capacity to do work (food provides nutrients which are used as building blocks for energy) 

metabolism

the sum of all the chemical reactions that occur within a cell or organism

what is the ultimate source of energy for life on earth

the sun

photosynthesis

used by plants, algae and some bacteria; harvests energy from the sun and converts it to chemical energy, produces sugars which serve at the basis for the food chain 

what are the 2 different types of metabolism and their function

catabolism; breakdowns complex molecules to smaller molecules (cellular respiration)

anabolism: generates complex molecules from simple molecules (photosynthesis)

homeostasis 

process of maintaining a relatively stable internal environment despite changes in external surroundings

homeostasis would be impossible to maintain without what?

ability to respond to stimuli (internal and external stimuli)

genes

short segments that specify traits

mutations

variations in genes; can be beneficial and make organisms better suited for its environment 

evolution 

how a population changes over time 

natural selection

the process by which evolution occurs

adaption

over time, a population has more individuals with this advantageous variation

prokaryotes 

single celled organism that lack a nucleus, bacteria and archaea contain these 

invertebrates 

most animals, lack internal skeletal support structure (worms, insects) 

vertebrates 

have a nerve cord protected by vertebral column (fish, reptiles, birds) 

mammals

vertebrates with hair/fur and mammary glands (humans, raccoons, seals)

culture

activities and items passed down from one generation to the next

science

a way of knowing about the natural world

discovery science

collection and analysis of data without a preconceived hypothesis

observation

formal way of watching the natural world

matter 

anything that has mass and takes up space 

elements

basic building blocks of matter; cannot be broken down by chemical means

90% of the human body is made up up which 4 elements

carbon, nitrogen, hydrogen, oxygen

atom

smallest unit of an element that retains its physical and chemical properties

molecules

atoms bonded together

subatomic particles (parts of an atom)

neutrons, protons, electrons

isotopes

atoms of the same element but a different number of neutrons

radioisotopes

unstable isotopes, they emit energy called radiation (can damage cells and cause cancer) 

compounds

molecules made of different types of atoms

what two types of bonds join atoms

ionic bonds and covalent bonds

ionic bonds

the attraction between a positive or negative ion, atoms donate or take electrons to fill their shell, resulting in formation of ions,

covalent bonds

atoms share electrons to fill their shells, these electrons will spend time in both atom shells

hydrogen bond

attraction between a slightly positive hydrogen to a slightly negative oxygen, nitrogen or fluorine

calorie

amount of heat required to raise one gram of water by one degree celsius

what must break for water to boil

hydrogen bonds

hydrophobic

molecules that do not attract water; are non-polar

hydrophilic

molecules that attract water; polar molecules

cohesion 

water molecules cling to each other through hydrogen bonds

adhesion

water molecules cling to surfaces like blood vessels 

extraterrestrial hypothesis

meteorites brought organic carbon to earth which includes amino acids and nucleic acid bases 

deep sea vent hypothesis

Biologically important molecules may have been formed in the temperature gradient between extremely hot vent water and cold ocean water

what are the organic molecules found in living cells

carbohydrates, lipids, nucleic acids, proteins

dehydration reaction

type of reaction that removes water, linking subunits together into macromolecules (large molecules) 

hydrolysis reaction

the addition of water to break macromolecules into their subunits

monosaccharides

simplest sugars (5-6 carbons); pentoses, hexose

polysaccharides

many monosaccharides linked together to form long polymers; starch, cellulose

lipids

40% of organic matter in humans, nonpolar, very insoluble in water; fats, phospholipids, steroids, waxes 

phospholipids

building blocks of cellular membrane

membranes

amphipathic phospholipids with saturated or unsaturated tails associate noncovalently to form bilayer membrane structure 

amphipathic

having both hydrophilic and hydrophobic parts

nucleic acids

carry coded information for making proteins at the right time and place; DNA, RNA

how many amino acids do we have

20- 11; can be synthesized, 9; from diet (essential)

carbohydrates

used as an energy source, carbon atoms linked to a hydrogen atom and a hydroxyl group; monosaccharides, disaccharides, polysaccharides

simple carbohydrates; monosaccharides

made up of single sugar molecule, has carbon backbone (3-7 carbons); glucose used as an immediate energy source 

disaccharides

made of 2 monosaccharides (from dehydration rxn); sucrose table sugar

complex carbohydrates; polysaccharides

long polymers of glucose subunits

what are the different types of polysaccharides you learnt about in class

starch: energy storage in plants

glycogen: energy storage in animals 

cellulose: structural in plant cell walls 

lipids

do not dissolve in water, lack hydrophilic polar groups; triglycerides, phospholipids, steroids 

triglycerides

type of hydrophobic lipid, made up of one glycerol and three fatty acids. Energy storage and insulation; fats, waxes and oils

emulsifiers

molecules that surround triglycerides and disperse or emulsify them.

waxes

one fatty acid attached to an alcohol, many plants and animals will produce waxes that are secreted onto their surface (ear wax)

fats vs oils

fats: usually animal origin, solid at room temp, energy storage, structural, insulation

oils: usually plant origin, liquid at room temp 

fatty acids

long chains of carbons and hydrogens, end in COOH, 16-18 carbons, saturated or unsaturated 

saturated vs unsaturated fatty acids

saturated: no double covalent bonds between carbons, they are saturated with hydrogen 

unsaturated: one or more double covalent bond because hydrogens are missing 

which type of fat contributes to heart disease the most

trans fats; man-made fats

phospholipids

similar structure to triglyceride but one fatty acid replaced with polar phosphate group. Have polar hydrophilic head and non-polar hydrophobic tails. Primary components of plasma membranes (form a bilayer) 

steroids

four rings of carbon atoms, insoluble in water; estrogen, testosterone

nucleic acid structure

polymers of nucleotides: a phosphate, 5 carbon sugar, nitrogenous base

nucleic acid functions

store information, instructions for essential life activity, chemical reactions; DNA, RNA

DNA vs RNA function

DNA: stores information on how to copy itself, specifies order of amino acids 

RNA: regulate enzyme action, stores energy, many functions, various types 

DNA makeup

formed from nucleotides; phosphate group, pentose sugar, nitrogenous base:(A,G,C,T)

RNA makeup 

phosphate group, pentose sugar, nitrogenous base; (A,C,G,U)

DNA structure

double stranded, antiparallel and complementary strands. Bases on the inside, stabilized by H-bonding

RNA structure

typically single stranded, nucleotides attached by 5’-3’ phosphodiester bonds between sugars. Base pairing via hydrogen bonds is basis of RNA secondary structure, tertiary structure is result of RNA folding.

ATP

high energy molecule, nucleotide like bases of DNA and RNA  but it stores and transports energy within cells. 

proteins

organic compounds built with chains of amino acids. Thousands of different types of proteins built by the body

protein functions

support, enzymes, defence, hormones, motion, transport

components of amino acids

an amino group, carboxyl group, and an R group. Each amino acid differs in its R group 

peptide bond

the polar covalent bond between two amino acids, formed by a dehydration reaction

polypeptide

three or more amino acids linked together

denaturation

the change in shape of a protein caused by extreme heat or pH; disrupts shape and function of protein

cell biology

the study of individual cells and their interactions with each other

cell theory

1. all living organisms composed of one or more cells

2. cells are the smallest units of life 

3. new cells come only from pre-existing cells by cell division 

what are the two categories of cells

prokaryotic and eukaryotic

prokaryotic cells

lack a nucleus, include two groups of bacteria; eubacteria and archaebacteria

eukaryotic cells 

have a nucleus, include animals, plants, fungi, protists 

what do both cell types have 

a plasma membrane that surrounds the cell made of phospholipid bilayer, a cytoplasm the semifluid substance inside the cell 

what were the first cells on earth 

prokaryotes, when the atmosphere had no oxygen

what did eukaryotic cells evolve from

from archaea via endosymbiosis; organelles may have developed from eukaryotes engulfing prokaryotic cells