Bio Unit 2

Front 1

base pairing

Back 1

A=T
C=G
hydrogen bonds

Front 2

three parts of a nucleotide

Back 2

phosphate group
pentose sugar
nitrogenous base

Front 3

RNA

Back 3

has ribose sugar
OH on 2nd carbon
uracil instead of thymine

Front 4

DNA

Back 4

has deoxyribose sugar
H on 2nd carbon

Front 5

phosphodiester bonds

Back 5

forms when two nucleotides are joined by dehydration synthesis
forms sugar phosphate backbone (nitrogenous base hangs off)

Front 6

prokaryotic DNA replication

Back 6

single origin of replication

Front 7

DNA replication

Back 7

polymerase adds nucleotides to 3' end
two strands are antiparallel
leading strands made in direction that bubble is opening
lagging strands made in pieces (okazaki fragments)
^^synthesized simultaneously but opposite directions

Front 8

central dogma

Back 8

DNA - RNA - protein

Front 9

mRNA

Back 9

contains info to build protein
not stable
messages interrupted by introns
includes 5' guanine cap and poly-A tail

Front 10

alternative splicing

Back 10

exon shuffling
can create multiple proteins from a single message

Front 11

exons

Back 11

often code for different functional domains in the protein

Front 12

tRNA

Back 12

shuttle amino acids to ribosome
folds back onto itself to create base pairing and complex 3-D shapes
nucleotides read in groups of 3 (codon)
decodes the message

Front 13

transcription (w/ 3 steps)

Back 13

produces RNA
copy of gene is made in same nucleotide language
base pairing between DNA template & growing RNA strand
RNA polymerase makes RNA copy of DNA
initiation: RNA binds to certain sequence on DNA (promoter) and begins synthesis
elongation: DNA is unwound and RNA polymerase adds nucleotides to growing RNA
termination: when RNA polymerase reaches the terminator sequence, transcription stops & RNA is released
*transcription factors required

Front 14

translation

Back 14

produces protein
info translated to amino acid language
ribosomes slide along mRNA adding amino acids to the protein through base pairing on the mRNA and anticodons on the tRNA
initiation of translation begins at first AUG on the message (sets reading frame)
elongation: codon recognition-tRNA flys in with amino acid, peptide bond forms-dehydration synthesis to form protein's peptide bond, translocation-ribosomes move from A-P-E positions
termination: translation terminates when ribosome hits a stop codon, all subunits come apart

Front 15

the genetic code is

Back 15

universal and redundant

Front 16

thymine dimers

Back 16

block DNA polymerase when DNA is damaged

Front 17

minimum requirements for a cell

Back 17

plasma membrane
genetic material
cytoplasm with ribosomes

Front 18

prokaryotic cell

Back 18

no membrane-bound organelles
just the three min requirements

Front 19

phospholipid bilayer

Back 19

amphipathic
in soln, lipid sandwich is spontaneously formed
proteins are embedded in and associated with the surface of it
fluid mosaic-lipids move laterally but rarely flip
impermeable to large, polar, or charged molecules

Front 20

diffusion

Back 20

spontaneous net movement of molecules from areas of high concentration to low concentration

Front 21

passive transport

Back 21

a diffusion of molecules through a membrane

Front 22

homeostasis

Back 22

an organism or cell's ability to maintain an internal environment separate from the external environment (b/c of selectively permeable membrane)

Front 23

facilitated diffusion

Back 23

movement of molecules down their concentration gradient with the help of protein channels or carriers in the membrane

Front 24

osmosis

Back 24

the diffusion of water thorough a selectively permeable membrane

Front 25

hypotonic

Back 25

lower concentration of solute, higher concentration of water
animal cells will explode (lysed)
normal (turgid) for plant cells

Front 26

hypertonic

Back 26

higher concentration solute, lower concentration water
animal cells shrivel
plant cells also shrivel (plazmolyzed), pull away from cell wall

Front 27

isotonic

Back 27

same concentration of solute
animal cells normal
plant cells flaccid (shrunken)

Front 28

active transport

Back 28

uses energy to move molecules against concentration gradient
use energy in H+ to move sucrose against concentration gradient

Front 29

endocytosis

Back 29

moves material into cells in bulk
phagocytosis
pinocytosis

Front 30

exocytosis

Back 30

bulk flow of material out of cells

Front 31

nucleus

Back 31

enclosed by double membrane
holds genetic material

Front 32

nucleolus

Back 32

appears as dark spot in nucleus where ribosomal RNA is made
not membrane-bound compartment

Front 33

ribosomes

Back 33

structures on which proteins are made
some free in cytoplasm, some bound to rough ER
have large and small subunit

Front 34

smooth ER

Back 34

lipid synthesis
carbohydrate metabolism
detoxification of drugs/poisons
storage of Ca ions

Front 35

rough ER

Back 35

has ribosomes attached to surface that make proteins to be inserted into the membrane, some destined for lysosomes or export
source of new membranes, makes phospholipids (like SER)
proteins on RER contain a signal sequence that docks the ribosome onto the ER

Front 36

vesicles

Back 36

pinch off of ER, often travel to golgi

Front 37

golgi apparatus

Back 37

packaging and distribution
molecules are modified by the addition of sugars, etc. as they pass through
materials oriented to the "inside" of the ER end up on the "outside of the cell

Front 38

lysosomes

Back 38

contents produced in RER and processed in golgi
function in digestion
phagocytosis
autophagy
*not present in prokaryotes

Front 39

vacuoles

Back 39

membrane bound compartments w/ different functions
central vacuoles in plants
contractile vacuoles in protists (pump out excess h2o)

Front 40

peroxisomes

Back 40

carry out rxns that produce h2o2 as byproduct
h2o2 = toxic so peroxisomes have enzyme to convert it to h2o

Front 41

chloroplasts

Back 41

convert light energy to chemical energy through photosynthesis

Front 42

mitochondria

Back 42

harvest food energy through cellular respiration
present in all cells

Front 43

cytoskeleton

Back 43

scaffolding that organizes cytoplasm
three different elements (microtubules, microfilaments, intermediate filaments)
cells change shape with this

Front 44

microtubules

Back 44

~25 nm, tube-like
organelles can move by "walking" on these
make up cilia, flagella, and mitotic spindles

Front 45

microfilaments

Back 45

actin
~7 nm
involved in muscular movement, pseudopodia
move chloroplasts around outside of plant cell

Front 46

intermediate filaments

Back 46

~8-12 nm
keratin
strong unchanging connectors

Front 47

plasmodesmata

Back 47

channels between plant cells through which cells can interact

Front 48

animal cells have... (as far as between their cells)

Back 48

tight junctions to seal them together
extracellular matrix involved in cell structure, adhesion, and communication
allow for free flow of materials through cells
some have gap junctions for rapid communication