anatomy ch 3 lecture Flashcards
1
Q
cell theory
A
1.) All living organisms are composed of cells.
2.) The cell is the basic unit of life.
3.) New cells arise only from pre-existing cells.
2
Q
how many different cell types are in humans
A
over 250
3
Q
three basic parts of human cells
A
plasma membrane
cytoplasm
nucleus
4
Q
extracellular materials
A
substances found outside of cells
5
Q
classes of extracellular materials
A
extracellular fluids
cellular secretions
extracellular matrix
6
Q
examples of extracellular fluids
A
interstitial fluids
blood plasma
cerebrospinal fluid
7
Q
function of plasma membrane
A
acts as active barrier separating intracellular fluid from extracellular fluid
controls what enters and leaves cell
8
Q
structure of plasma membrane
A
phospholipid bilayer
membrane proteins
glycocalyx
cell junction
9
Q
integral proteins
A
transmembrane protein
hydrophobic and hydrophilic regions
transport proteins, enzymes, receptors
10
Q
peripheral proteins
A
loosely attached to integral proteins
on intracellular surface used for plasma membrane support
11
Q
transport proteins
A
span membrane
provide channel across for particular solute
12
Q
glycocalyx
A
carbohydrates sticking out of cell surface
cell recognition
allows immune system to recognize self vs nonself
13
Q
what are the three ways cells can be bound together
A
tight junctions
desmosomes
gap junctions
14
Q
tight junctions
A
impermeable junction
prevent fluids and molecules from moving in between cells
ex. stomach lining
15
Q
desmosomes
A
connect cytoskeletons of neighboring cells
allow “give” between cells
ex. skin
16
Q
gap junctions
A
transmembrane proteins from tunnels that allow small molecules to pass from cell to cell
ex. involuntary muscles
17
Q
passive transport
A
no energy required
18
Q
active transport
A
energy (ATP) required
19
Q
plasma membrane is _____ permeable
A
selectively
20
Q
what are the three types of passive transport
A
simple diffusion
facilitated diffusion
osmosis
21
Q
simple diffusion
A
molecules move from high to low concentration
22
Q
how is the speed of diffusion influenced (3)
A
concentration
molecular size
temperature
23
Q
facilitated diffusion
A
molecules move down the concentration gradient through the use of protein channels or carriers
24
Q
osmosis
A
movement of water molecules from high to low concentration across a semipermeable membrane
25
carriers
transmembrane integral proteins
26
what do carriers transport
specific POLAR molecules, too large for membrane channels
sugars, amino acids
27
when are carriers saturated
bound to molecules and busy transporting
28
channel-mediated facilitated diffusion
channels transport molecules down concentration gradient
ions, water
29
what are the two types of channel-mediated diffusion
leakage channels
gated channels
30
leakage channels
always open
31
gated channels
controlled by chemical or electrical signals
32
aquaporins
specific channels for water
33
osmolarity
the concentration of the total number of SOLUTE particles in solvent
34
T/F: osmosis results in volume changes on both sides of a semi-permeable membrane
true
35
hydrostatic pressure
the force exerted by water inside the cell pushing against the cell membrane.
36
osmotic pressure
the force that's needed to prevent water from moving into the cell due to differences in solute concentrations.
37
what happens to the movement of water when hydrostatic pressure = osmotic pressure
no net movement of water
38
tonicity
ability of a SOLUTION to change shape/tone of cells by altering cells internal water volume
39
isotonic solution
same osmolarity inside and outside cell
volume is unchanged
40
hypertonic solution
solution has higher solute concentration than cell
water leaves cell
cell shrinks
41
crenation
cell shrinks
42
hypotonic solution
solution has lower solute concentration than cell
water enters cell
cell swells
43
lysing
cell bursting
44
what are the two major active membrane transport processes
active transport
vesicular transport
45
why would a cell need to use active transport
solute too large for channels
solute is not LIPID soluble
solute is moving against concentration gradient
46
antiporter
transport one substance OUT and one substance IN
47
symporter
transport TWO different substances in the SAME direction
48
do symporters and antiporters require energy (ATP)
yes
49
primary active transport
required energy comes DIRECTLY from atp hydrolysis
49
what are the two types of active transport
primary and secondary
50
secondary active transport
required energy comes INDIRECTLY from ionic gradients created ny primary active transport
51
what are examples of primary active transport pumps
SODIUM-POTASSIUM
calcium
hydrogen (proton)
52
sodium-potassium pump
NA+ out of cell
K+ back into cell
in all plasma membranes
53
vesicular transport
active transport involving larger particles in vesicles
endocytosis and exocytosis
54
endocytosis
transport INTO cell
protein coated vesicles
55
types of endocytosis
phagocytosis
pinocytosis
receptor-mediated cytosis
56
exocytosis
transport OUT of cell
secretory vesicle
57
transytosis
transport into, across, and then out of cell
58
vesicular trafficking
transport from one area/organelle in cell to another
59
phagocytosis
cell eating
phagosome
moves via amoeboid motion (to creep!!)
60
pinocytosis
cell drinking
brings in extracellular fluid
fuses with endosome
61
receptor-mediated endocytosis
for specific molecules
receptors embedded in clathrin-coated pits
62
resting membrane potential
electrical charge difference across cell membrane
cells with charge are POLAR
63
what is a key player in resting membrane potential
K+
64
most cells have RMP around _____
-90 mV
K+
65
what sets RMP
electrochemical gradient of K+
66
if Na+ enters cell what is the RMP at
-70 mV
67
what is the primary influence of RMP
K+
membrane more permeable to it than Na+
68
what are the two interactions between cells and their envirorment
cell adhesion molecules (CAMs)
plasma membrane receptors
(both involve the glycocalyx)
69
contact signaling
cells that touch recognize each other by each cell's unique surface membrane receptors
70
chemical signaling
interactions between receptors and ligands that cause changes in cellular activities
71
what is the cytoplasm composed of
cytosol
inclusions
organelles
72
cytoplasm
all cellular material located between plasma membrane and nucleus
73
what are the non membranous organelles
ribosomes
cytoskeletons
centrioles
74
what are the membranous organelles
mitochondria
ER
golgi
peroxisomes
lysosomes
75
membranes allow _______
compartmentalization
76
mitochondria
produces most of cells energy molecules (ATP) via aerobic cellular respiration
77
aerobic
requires oxygen
78
cristae
folds of the inner membrane in mitochondria
79
mitochondria contain their own ____,____, and _____
DNA, RNA, and ribosomes
80
what type of division can mitochondria undergo
fission
same type as bacteria
81
ribosomes
protein synthesis
82
what are the two forms of ribosomes
free (floating) and membrane bound (attached to ER)
83
rough ER
studded with attached ribosomes
final protein produced sent to golgi
84
smooth ER
looped tubules
lipid metabolism
absorption, synthesis, and transport of fats
detoxifies chemicals
converts glycogen to free glucose
stores and releases calcium
85
golgi
modifies, concentrates, and packages proteins & lipids received from rough ER
86
three steps in the golgi
1. transport vesicles from ER fuse with face of golgi
2. proteins/lipids taken in
3. controls which path it will take
87
peroxisomes
membranous sacs that DETOXIFY substances
breakdown/synthesis of fatty acids
88
lysosomes
membranous sacs that contain DIGESTIVE enzymes
digests bacteria, viruses, toxins
89
autoysis
cells digest themselves
90
endomembrane system
consists of
ER
golgi
secretory vesicles
lysosomes
nuclear and plasma membranes
91
function of endomembrane system
produce, degrade, store, export biological molecules
degrade potentially harmful substances
92
cytoskeleton
network of rods that run through cytosol
three types
93
three types of cytoskeleton
microfilaments
intermediate filaments
microtubules
94
microfilaments
thinnest
semi-flexible strands of ACTIN
cell motility, changes in cell shape, endo/exocytosis
95
intermediate filaments
tough, ropelike protein fibers
helps cell resist pulling forces
96
microtubules
largest
hollow tubes composed of proteins called TUBULINS
determine overall shape of cell
97
motor proteins
complexes that function in motility
movement of organelles/substances around a cell
98
centrioles
form the basis of cilia and flagella
help in cell division
99
cilia and flagella
aid in cell movement
100
microvilli
fingerlike projections that increase cell surface area
core of actin filaments
101
nucleus
largest organelle
holds genetic information
102
multinucleate
many nuclei
skeletal muscles
102
uninucleate
one nucleus
most cells
103
anucleate
no nucleus
red blood cells
104
three main structures of nucleus
nuclear envelope
nucleoli
chromatin
105
nuclear envelope
double membrane layer that encloses the nucleoplasm
106
nuclear pores
allow substances to pass in and out of nucleus
107
nucleoli
spherical bodies in nucleus involved in rRNA synthesis
one/two per cell
108
chromosomes
condensed chromatin
arranged in nucleosomes
30% threadlike strands of DNA
60% histone proteins
10% RNA
109
two major periods of the cell cycle
interphase
cell division (mitotic phase)
110
interphase
period from cell formation to division
111
interphase subphases
G1
S (synthetic)
G2
112
G1 phase
cell growth and metabolism
113
S phase
synthetic phase
DNA replication occurs
114
G2 phase
preparation for division
115
G0 phase
cells that permanently cease dividing
116
mitotic phase events
mitosis
cytokinesis
117
M phase stages
prophase
metaphase
anaphase
telophase
118
prophase
early: chromatin condenses, centrosomes pushed to opposite sides of cell
late: nuclear envelope breaks up, poles of cell move farther apart
119
metaphase
centromeres of chromosomes lined at cells equator
metahphase plate
120
anaphase
shortest phase
chromosomes split
chromosomes pulled toward opposite sides
121
telophase
new nuclear membranes form around each chromatin mass
122
cytokinesis
cleavage furrow
two daughter cells are pinched apart
123
what determines when a cell should or should not divide
go and stop signals
go: surface to volume ratio of cell, chemicals
stop: contact inhibition (availability of space)
124
gene
segment of DNA that holds code for one polypeptide
composed of exons and introns
125
exons
codes for amino acids
126
introns
noncoding segments
127
mRNA
single stranded
maintains triplet code from DNA
128
rRNA
structural components of ribosomes
129
tRNA
carrier of amino acids
130
three phases of transcription
initiation
elongation
termination
131
how many possible codons are there
64
132
how many stop codons are there
3
UAA
UGA
UAG
133
what is the start codon
AUG
134
events in translation
initiation
elongation
termination
135
what is the initiator tRNA
methionine
136
autophagy
self eating
cells become obsolete/damaged and need to be taken out of system
137
apoptosis
programed cell death
