Bio ch 1-3 concepts

8 properties of life

order, response, reproduction, adaptation, growth/development, regulation/homeostasis, energy processing, evolution

order

living things are highly organized structures made of one or more cells. body isn’t just a random collection of molecules

sensitivity/response

living things respond to changes in their environment. like how plants bend toward light. plants bend toward light

chemotaxis

movement in response to a chemical

phototaxis

movement in response to light

reproduction

living things produce offspring. because of DNA, offspring look like their parents

adaptation

a characteristic that helps an organism survive and reproduce in its environment. polar bears have fur to keep them warm

__ is a result of evolution

adaptation

growth and development

organisms change as they grow because their genes contain instructions. this is how a kitten turns into a cat

regulation/homeostasis

maintaining a relatively stable internal environment. outside environments can change, but your body tries to keep its internal conditions within a suitable range

energy processing

living things need energy. there are different ways for organisms to obtain energy. plants get energy from the sun - convert to chemical energy - stored in food

__ powers the processes of life

energy

evolution

gradual change in populations over generations

atom

smallest unit of matter/element

molecule

two or more atoms chemically bonded

macromolecule

large biological molecule (DNA/proteins/carbs)

organelle

structure inside a cell that performs a particular function (nucleus/mitochondria)

cell

smallest fundamental unit of life.

tissue

group of similar cells performing a common function.

example:

muscle cells → muscle tissue

organ

multiple tissues working together for a specific function.

example:

different tissues → heart

organ system

multiple organs working together

example:

heart + blood vessels → circulatory system

organism

an individual living thing

example: you

population

all individuals of one species in an area

community

all populations of different species in an area

ecosystem

community + nonliving environment

biosphere

all ecosystems on earth

prokaryotes

no nucleus, no membrane - bound organelles, generally single-celled, bacteria and archaea

eukaryotes

have a nucleus, have membrane-bound organelles, can be single celled or multicellular, animals/plants/fungi/etc

three domains of life

bacteria, archaea, and eukarya

binomial nomenclature

every species gets two names - genus + species (homo sapiens)

phylogenetic tree

shows how organisms are related based on evidence such as genetic similarities. family tree for species

hypothesis

testable explanation for an observation

scientific theory

thoroughly tested and confirmed explanation for a set of observations.

scientific law

description of how some aspect of nature behaves under specific conditions, often mathematically.

inductive reasoning

you observe many individual examples.

then you form a general conclusion.

example:

you observe:

bird #1 has feathers.

bird #2 has feathers.

bird #3 has feathers.

bird #4 has feathers.

↓

you conclude:

birds have feathers.

deductive reasoning

start with a general principle.

use it to predict something specific.

example:

general principle:

climate warming causes species distributions to change.

↓

prediction:

if this region gets warmer,

↓

the distribution of its plants and animals should change.

scientific method

observation - question - hypothesis - prediction - experiment - analyze results - conclusion

variable

something that changes in an experiement

control

the comparison condition that doesn't receive the experimental treatment.

basic science

knowledge for the sake of understanding

applied science

uses scientific knowledge to solve a practical problem

serendipity

a fortunate accidental discovery

matter

anything that occupies space and has mass

matter is made up of ___

atoms

element

a substance consisting of one type of atom

there are __ naturally occurring elements

92

atoms contain three major subatomic particles

protons, neutrons, electrons

proton =

positive

neutron =

neutral

electron =

negative

atomic number

the number of protons in an atom

neutral atom

number of protons = number of electrons

mass number

protons + neutrons

isotopes

atoms of the same element that have different numbers of neutrons

isotopes do NOT have different numbers of ___

protons

chemical bonds

atoms can interact with one another to form molecules and compounds

chemical bonds happen because of ___

electrons

ionic bonds

results from the attraction between oppositely charged ions after electrons are transferred

covalent bonds

forms when atoms share electrons

nonpolar covalent

electrons are shared relatively equally

polar covalent

electrons are shared unequally

one atom attracts the shared electrons more strongly

hydrogen bonds

a weak attraction involving partial charges between molecules or parts of molecules

much weaker than covalent bonds

van der waals interactions

weak attractions that occur when molecules/atoms are very close and their electrons create temporary uneven distributions of charge

water is __ because electrons are shared unequally, creating partial charges

polar

cohesion

attraction between molecules of the same substance

surface tension

the result of cohesive forces at the surface of a liquid

this is how insects can walk on water

cohesion + hydrogen bonding =

surface tension

solvent

a substance that dissolves other substances

pH

measures the concentration of hydrogen ions in a solution

acidic pH scale

0-6

neutral pH scale

7

basic pH scale

8-14

1 unit pH difference =

10x difference in H

buffer

helps prevent large changes in pH when acids or bases are added

can help cells stay within appropriate chemical conditions

four major biological macromolecule categories

carbohydrates, lipids, proteins, and nucleic acids

livings things are often described as __

carbon-based

carbohydrates

can provide energy, structural support, and cell recognition

monosaccharides

a single sugar unit

examples: glucose, fructose, and galatose

disaccharides

consists of two sugar units

polysaccharides

starch & cellulose

contains many sugar units

lipids

fats, oils, waxes, phospholipids, steriods

most are nonpolar and hydrophobic - “water fearing”

triglycerides

fats and oils commonly consist of glycerol + fatty acids =

long term energy storage

functions of lipids

energy storage, cell membranes, waterproofing, insulation, and signaling

phospholipids

major components of the plasma membrane

head likes water, tail avoid water

proteins

extremely diverse and perform many functions including structural support, enzymes, carriers, hormones, and metabolism

amino acids

the building blocks of proteins

denaturation

occurs when a protein loses its normal shape

nucleic acids

DNA and RNA

involved in directing cellular activities like cell division and protein synthesis

nucleotides

the building blocks of nucleic acids are called

DNA

Stores hereditary/genetic information

RNA

Helps use genetic information, particularly in protein synthesis

cell theory

all organisms are composed of one or more cells

the cell is the basic unit of life

all new cells arise from existing cells

__ cells use membranes to separate tasks into specialized areas. for example, the nucleus protects DNA, while mitochondria product ATP

eukaryotic

__ cells do not have membrane-bound organelles, but they still carry out all essential life processes

prokaryote

all prokaryotes have

plasma membrane

cytoplasm

ribosomes

DNA

usually a cell wall

no membrane-bound organelles

all prokaryotes and eukaryotes share

plasma membrane

cytoplasm

ribosomes

DNA

a typical prokaryotic cell compared to a eukaryotic cell is

smaller in size by a factor of 100

plasma membrane

separates the cell from its surroundings and controls what enters and leaves

cytoplasm

provides structure and is the site of many metabolic reactions

nucleus

houses DNA and directs the synthesis of ribosomes and proteins