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47 terms

Bio Midterm ch. 7

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the cell theory
all cells are produced by existing cells, cells are the basic unit of life, and all living things are made up of cells
a nucleus
prokaryotes lack _____________
genetic material, specialized organelles, a nucleus
eukaryotes contain _________________________________
bacteria
an example of a prokaryote is
ribosome
which is found in the cytoplasm? a)nucleolus b)ribosome c)chromatin d)cell wall
ribosome
which structure makes protein using coded instructions that come from the nucleus
mitochondria and chloroplasts
which organelles help provide cells with energy?
rough er, golgi apparatus, released from the cell
what is the sequence an path of a protein in the cell?
chloroplast
which organelle would you expect to find in plant cells but not animal cells?
helps a cell keep its shape and is involved in movement
what are the functions of the cytoskeleton?
support and protect the cell
the main function of the cell wall is to ___________________
regulates which materials enter and leave the cell, separates the cell from their surroundings, protection and support
what are the functions of the cell wall?
proteins
the cell membrane contains channels and pumps that help move materials from one side to the other. What are these cahnnals and pumps made of?
diffusion
__________ occurs because molecules constantly move and collide with each other
active transport
what means of particle transport that requires input of energy from the cell?
osmosis
the diffusion of water across a selectively permeable membrane is called ________
moe across the membrane in both directions
when the concentration of molecules on both sides of a membrane is the same, the molecules will ______________________
Schleiden
realized all plants were made up of cells
Schwann
realized all animals were made up of cells
Hooke
examined cells in a sample of cork
Virchow
realized cells arive from preexisting cells
Brown
identified the nucleus of the cell
cell wall
cell structure: in plant cells, fungi, and bacteria; outside the cell membrane; permeable
nucleus
cell structure: large, and not found in all cells; the information center of the cell, contains genetic information, directs cell activity; contains chromatin composed on DNA plus protein
nucleolus
cell structure: made up of RNA and protein; ribosomes are made here
nuclear envelope
cell structure: is permeable, has a double membrane with pores
cytoplasm
cell structure: the area between the nucleus and the cell membrane
ribosomes
cell structure: smallest organelle; RNA and protein, may be free in the cytoplasm or attached to the rough er, proteins are made here!
rough er
cell structure: a system of channels, continues with the outer membrane of the nuclear envelope; ribosomes are attached; proteins are synthesized at the ribosomes and enter this where they may be modified functional
smooth er
cell structure: no ribosomes; synthesizes lipids; detoxificationof drugs; (many found in liver cells) molecules produced or modified here are enclosed in vesicles and then transported to the golgi apparatus
golgi apparatus
cell structure: consists of a stack of 3 to 20 curved membranes; modifies, sorts, and packages molecules from the er; contains enzymes that modify proteins and lipids; "customizes"; vesicles that leave this move to different locations in the cell or outside the cell
vacuoles
cell structure: membrane-enclosed sacs function to store water, sugars, salts, and pigments; small _____ are called vesicles; plant cells have a large, main ______
lysosome
cell structure: contains digestive enzymes that digest macromolecules and bacteria, old materials in the cell
mitochondria
cell structure: makes ATP, site of chemical reactions that extract energy from food; double membranes; all eukaryotic cells have them; uses energy to move
chloroplast
cell structure: surrounded by double membrane; found only in plants; photosynthesis takes place; contains cholorphyll, a pigment; has its own DNA
active transport
substances are able to move from an area of lower concentration to an area of a higher concentration; requires energy; moves ions; molecular transport-protein pumps, proteins change shape
passive transport
no energy required; moving from an area of higher concentration to an area of lower concentration
hypertonic
more solute outside of the cell; water moves to lower concentration; cell shrinks
isotonic
equal amounts of solute and solvent; is equilibrium
hypotonic
more solute inside of the cell; cell expands and may explode
solute
substance dissolved in a liquid, commonly salt
solvent
liquid, commonly water
phosolipids, protein pumps, and carbohydrate chains
a cell wall is composed of ___________________
hydrophilic
the "heads" in phosolipids are called _________ because they touch water
hydrophobic
the "tails" in phosolipids are called _________ because they dont touch water
fluid mosaic
a lipdi bilayer or the cell membrane is sometimes called a ______________
cell membrane
cell structure: proteins form a mosaic pattern; the proteins act as channels or pumps through which molecules can pass; carbohydrate chains are used as chemical identification