Biology Midterm Review

cells

smallest units of life

prokaryote

no nucleus; no membrane-bound organelles

eukaryote

has a nucleus; membrane-bound organelles

mitochondria

makes ATP

ribosomes

carry out protein synthesis

chloroplasts

absorb sunlight for photosynthesis

cell wall

found in plants and prokaryotes; surrounds the cell membrane

vacuole

stores water in plants; takes up most of the plant area

phospholipids

bilayer that forms the cell membrane

protein

transporters, enzymes, receptors

diffusion

passive transport; moves particles from high to low concentration

facilitated diffusion

passive transport; uses a protein carrier to move molecules from high to low concentration

osmosis

passive transport of water from a low to high solute concentration

active

transport that uses ATP to move molecules against their concentration gradient (low to high)

mitosis

shortest part of cell division

interphase

phase where the cell is growing and preparing for division

S (synthesis)

DNA is replicated during this phase

metaphase

prophase

telophase

anaphase

cytokinesis

asexual reproduction

one parent cell/organism produces identical offspring

condensation

hydrolysis

carbohydrates

sources of quick energy; contain the elements C, H, and O

lipids

sources of long term energy; insulators; make up the cell membrane

nucleic acids

DNA and RNA

glucose

amino acid

nucleotide

triglyceride

saturated fatty acid

unsaturated fatty acid

cohesion

water molecules stick together

adhesion

water molecules stick to other things

monosaccharides

glucose, fructose, galactose, ribose

disaccharides

sucrose, lactose, maltose

polysaccharides

cellulose, glycogen, starch

enzyme

a catalyst and a protein

denature

when an enzyme's active site is changed

hydrogen

bond that holds DNA bases together

covalent

bond that connects sugar-phosphate backbone of DNA

peptide

bond that connects amino acids

transcription

DNA --\> mRNA in the nucleus

translation

mRNA --\> amino acid --\> protein at the ribosome

replication

DNA --\> DNA during interphase

cell theory

1. all living things are made of cells
2. cells are the smallest unit of life
3. cells come from preexisting cells

membrane protein functions

Transport (protein channel), Receptors (for hormones), Anchorage (cytoskeleton attachments), Cell recognition (antigens), Intercellular joinings (tight junctions), Enzymes

evidence against davson-danielli model

freeze fracturing, fluorescent antibody tagging, biochemical techniques

davson-danielli model

singer-nicolson fluid mosaic model

properties of water

thermal: high specific heat capacity, high heat of vaporization, & high heat of fusion

cohesive: water sticks to water molecules. adhesive: water sticks to other molecules

solvent: water can dissolve many substances with charges/polar regions

autotroph

an organism that makes its own food

heterotroph/consumer

an organism that gets its energy from another living organism

saprotroph

secretes digestive enzymes and absorbs non-living organic matter to get energy

detritivore

ingests non-living organic matter

mesocosm

a biological system that contains biotic and abiotic features of an ecosystem but is restricted in size and/or are under controlled conditions

food chain

shows the flow of energy through the trophic levels of a feeding relationship

primary consumer

an organism that eats producers

secondary consumer

an organism that eats primary consumers

community

a group of populations living and interacting with each other in the same area

species

a group of organisms that can interbreed to produce fertile offspring

ecosystem

a community and its abiotic environment

greenhouse effect

the natural warming of the earth’s surface

global warming

a gradual increase in average global temperature

peat

partially decayed plant matter found in bogs

trophic level

each step in a food chain/web

saprotroph examples

bacteria; fungi

detrivore examples

earthworm; pillbug