Bio Test 2 Flashcards
heterochromatin
condensed non-coding DNA, very compact, don’t open for transcription, black areas in nucleus
euchromatin
loose DNA, white parts in nucleus, many genes, active transcription
nuclear envelope
has 2 layers of membranes (2 bilayers)
endoplasmic reticulum
extension from nuclear membrane, single layer organelle, 10% of cell
rough endoplasmic reticulum
contains ribosomes; protein translation, folding and transport
smooth endoplasmic reticulum
no ribosomes; synthesis of lipids and steroids, metabolism of carbs
golgi apparatus
lipid synthesis, pancake-like structure, protein modification and packaging and sorting, proteins move from inside cell to outside
sarcoplasmic reticulum
special type of smooth ER found in muscle, contains Ca+ which are released for muscle contraction
mitochondria
double membrane organelle, have DNA, glucose used to form ATP
chloroplast
double membrane organelle, have DNA, use carbon dioxide and light to create glucose
lysosome
containing digestive enzymes, digestive center, homogenous, maintain acidic environment by pumping in H+ ions
peroxisome
containing enzymes that break down long fatty acid chains, detoxification center
antibodies
produced by b-cells or b lymphocytes, coat pathogen which are then detected by WBC to engulf them to being them to the lysosome to break down
affinity chromatography
beads coated with antibodies to purify antigen
immunostaining
primary antibody and secondary antibody
nucleolus
rRNA synthesis, assembly of ribosomal subunits
plasma membrane
encloses the cell
cytoplasm
fills interior of cell
genetic material within cell
prokaryote: circular form
eukaryotes: linear form (helix)
what determines the diffusion rate of molecules
size and solubility
readily diffused molecules
small hydrophobic molecules
small uncharged polar molecules
impermeable molecules
ions
larger uncharged polar molecules
types of membrane transport proteins
transporter
channel proteins
transporter proteins
have specific binding sites for ions and compounds, carry it across membrane
channel protein
mainly for ions by size and charge, opens and closes to allow molecule through
passive transport
doesn’t require energy, goes with concentration gradient
active transport
does require energy, goes against concentration gradient
types of active transporters
coupled transporter
ATP-driven pump
light-driven pump
coupled transporter
uses energy from one molecule to facilitate the other other molecule against the concentration gradient
ATP-driven pump
ion pump, changes formation of protein, one moves against concentration gradient
light-driven pump
mainly in bacteria, uses energy from light to move substance against concentration gradient
Na+-K+ pump
example of coupled transport
uses ATP to pump Na+ out and K+ in
30% of ATP consumed by carrier protein
cyclic action of carrier protein
concentrations higher on outside the cell
Na+, Ca2+, Cl-
concentrations higher inside the cell
K+, H+
electrochemical gradient
concentration gradient + membrane potential
symport
transport 2 molecules in same direction
example of symport
glucose-NA+
driven by Na+ electrochemical gradient
ion channels
ion selectivity requires specific signal to open or close more then 10^6 ions pass through per sec change membrane potential force other ions channels to open or close in millisecond generate electric signal across membrane will only accept one kind of ion mainly for Na+, K+, Cl- and Ca2+
ion selectivity
depends on diameter and shape of ion channel and the distribution of charged amino acids in lining
gated ion channel
channel that requires specific signal to open or close
patch-clamp recording
technique used to study behavior of ion channels
process of patch-clamping
glass microelectrode (d=1 micrometer)
attach to cell membrane
detach patch which contains ion channels
metal wires connected to beaker and glass microelectrode
apply voltage and record current with oscilloscope
test effects of chemicals or membrane conditions
