The Cell Flashcards
1
Q
The emergence of life from non-living material
A
abiogenesis
2
Q
Outer boundary of the cell which acts as a selectively permeable barrier.
A
plasma membrane
3
Q
Proteins embedded in membrane move around
A
“Fluid Mosaic”
4
Q
plasma membrane embedded with…
A
cholesterol
proteins
glycolipids
glycoproteins
5
Q
hydrophilic heads
A
hydrophobic tails
6
Q
5 Major Functions of Cell Membrane
A
Mechanical barrier (separates extracellular fluid from intracellular fluid) Selective permeability Electrochemical gradient Communication Cell signaling
7
Q
Phospholipids can move back and forth, but…
A
they do not flip sides!
8
Q
lipid + sugar
A
glycolipid
9
Q
2 glycolipid functions
A
Facilitates cellular recognition and cell-to-cell interactions
Constitutes about 5% of the cell membrane
10
Q
Cholesterol functions
A
Regulates membrane fluidity
Constitutes about 20% of the cell membrane
11
Q
“Sugary coating” made of glycolipids;
cell-to-cell recognition and facilitates cell’s interaction with environment
A
glycocalyx
12
Q
glycocalyx made of…
A
CAMs and membrane receptors
13
Q
embryonic development, wound repair, immunity
A
CAM’s (cellular adhesion molecules)
14
Q
Contact signaling, chemical signaling
A
membrane receptors
15
Q
protein inserted into membrane
A
integral
16
Q
not inserted proteins
A
peripheral
17
Q
“Cell glue” that helps hold body’s cells together
Proteins, carbohydrates secreted by cells
A
Extracellular Matrix
18
Q
Interstitial fluids (nutritious “soup” that bathes cells)
Blood plasma
Cerebrospinal fluid
A
Extracellular Fluid
19
Q
Digestive juices, lubricants, etc
A
Cellular Secretions
20
Q
Order of Layers
A
Epithelial
Basal Lamina
Connective Tissue (collagen fibers)
21
Q
Prevent digestive juices and microbes from escaping digestive tract
A
Tight Junctions
22
Q
Reduce tearing in tissues subjected to mechanical forces (skin, heart)
“Velcro” or “Rivets”
A
Desmosomes
23
Q
Electrically excitable tissues (heart, smooth muscle)
A
Gap junctions
24
Q
2 kinds of passive transport (no energy input required)
A
Diffusion --Simple diffusion --Facilitated diffusion --Osmosis Filtration (across capillary walls)
25
2 kinds of active transport (usually ADP or GTP)
Active transport
--Primary
--Secondary
Vesicular transport
26
Diffusion
particles naturally spread out
27
When is a cell in equilibrium with its environment?
when it is dead
28
Net osmosis depends on number (not (blank)) of solute particles
solute concentration increases, water concentration decreases
29
total concentration of all solutes
osmolarity
30
isotonic
cells retain normal size and shape in solution (same solute: water concentration as inside cells)
Ex: ECF, IV drip
31
hypertonic
cells lose water and shrink
(contains higher nonpenetrating concentration than inside the cell)
ex: ocean water
32
hypotonic
cells take on water until they burst
surrounding solution contains lower {} of nonpenetrating solutes than inside the cells
ex: distilled water
33
simple diffusion
from area of higher [] to lower []
34
facilitated diffusion
attached to a protein and carried through channel
35
primary active transport
Req hydrolysis of ATP
Phosphorylated pump changes shape, allowing it to move particles
Example: Na+-K+ pump transports ions against their electrochemical gradient
Sodium accumulates outside the cell; potassium accumulates inside the cell
36
Relies on electrochemical gradient est. by primary active transport
A particle actively transported across membrane can do work as it diffuses back
Example: Na+-glucose transporter (symporter)
secondary active transport
37
Symport system
Both particles move in the same direction
38
Antiport system
Particles move in the opposite direction
39
vesicular transport
```
large particles (proteins) bubble-like sacs called vesicles
requires ATP
```
40
Importing
endocytosis
41
exporting
exocytosis
42
into, across, out of cell
transcytosis
43
vesicular trafficking
move stuff around cell, FedEx
44
3 vesicle fates
Recycling
Fusion with lysosome and digestion
Transcytosis
--important for endothelial cells (line blood vessels)
--Allows nutrients to quickly go from bloodstream to interstitial fluid
45
3 types of endocytosis
phagocytosis
pinocytosis
receptor-mediated endocytosis
46
phagocytosis
Targets material for digestion or destruction by fusing with lysosome
Non-specific
47
pinocytosis
Cell “samples” ECF gather up solutes
| Non-specific
48
Receptor-mediated endocytosis
cell to concentrate and import certain substances
| hijacked by influenza and cholera
49
Listeria
pathogen hijacks cells
50
secretory vesicles secrete (by exocytosis)
Hormones
Neurotransmitters
Waste
51
“Negative” means the inside of the cell is negative
membrane potential
52
Na: K pump ratio
3 Na: 2 K
| maintains isotonic environment (w/respect to ECF)
53
: Substances that may be present depending on the type of cell
inclusions
54
Properties of both colloids and solutions; contains salts, proteins, sugars, etc. dissolved in water
cytosol
55
contain own DNA and ribosomes (can replicate themselves)
aerobic respiration
double membrane (2 bilayers)
mitochondria
56
Synthesize protein
ribosomes
57
ribosome location
free in cytosol
| bound to rough ER (make proteins for transport)
58
Endomembrane system (produce/store things, kill invaders)
```
Endoplasmic reticulum
--Rough
--Smooth
Vesicles
Golgi apparatus
Lysosomes
Nuclear membrane`
```
59
Hosts ribosomes that produce proteins
Rough ER (First, proteins to Golgi apparatus;
Then, secreted (exported) shipped to membrane
--hosts enzymes make phospholipids
60
Continuous w/ rough ER
No ribosomes
hosts enzymes
Smooth ER
61
what kind of enzymes does the smooth ER host?
- -Lipid metabolism
- -hormone synthesis
- -Detoxification
- -Breakdown of glycogen to release glucose
62
Golgi Apparatus ("FedEx")
Vesicles received from ER at cis face
Proteins modified then tagged for delivery and shipped from trans face via one of three types of vesicles:
--Secretory vesicles (granules): Secretion via exocytosis
--Vesicles with proteins or lipids destined for cell membrane
--Vesicles with digestive enzymes become lysosomes
63
Vesicles that allow the cell to digest things safely
| The inside is acidic and contains digestive enzymes (acid hydrolases)
Lysosomes
64
lysosome functions (3)
Digest macromolecules
Destroy microbial invaders (phagocytes)
Recycling (proteins, organelles) – known as autophagy
Autolysis: Lysosome ruptures and spills contents into cell, and the cell dies
65
Molecules with a single unpaired electron
peroxisomes
66
peroxisomes (destroy free radicals and other toxins)
Oxidases convert free radicals to hydrogen peroxide (H2O2)
| Catalases convert H2O2 to water
67
3 types of cytoskeleton
Microfilaments
Intermediate filaments
Microtubules
68
“web” made of actin
Strengthen cell surface, resist compression, movement
Constantly break down and re-form
microfilaments
69
permanent “woven rope” attaches to desmosomes
Resists pulling forces exerted on cell (prevents tearing)
maintain cell shape
intermediate filaments
70
hollow tubes made of“tubulin”; constantly break down and reassemble
Serve as “scaffolding” (i.e. cell shape and positioning of organelles)
Motor proteins -- organelles around on the microtubules
Associated with centrosomes (and the mitotic spindle)
microtubules
71
paired centrioles
| Organizes mitotic spindle (mitosis)
centrosomes
72
nine triplets of microtubules (9 x 3)
In centrosomes, centrioles are found in pairs, at right angles
--form the bases of cilia and flagella
centrioles (churro)
73
3 parts of nucleus
Nuclear envelope (membrane)
Nucleolus (singular) or nucleoli (plural)
Chromatin
74
which cells do not have nuclei
red blood cells
75
Double-membrane
Outer mem continuous with rough ER
Inner membrane (nuclear lamina – a protein scaffold nucleus shape & organizes DNA)
nuclear envelope
| also contains nuclear pores and nucleoplasm
76
Contains rRNA genes (DNA), RNA, enzymes, and other proteins
nucleolus
77
DNA wraps twice around 8 histone proteins
nucleosome ("units" of chromatin)
78
Routine cellular activities
G1 (gap 1):
79
DNA replicates
S phase
80
stopped dividing
G0 phase
81
enzyme unwinds the DNA double helix
helicase
82
Synthesizes RNA primer
primase
83
Adds nucleotides to produce the DNA polymer
DNA polymerase
84
Seals the “nicks” in the lagging strand
ligase
85
metaphase
Chromosomes line up in the middle
86
Anaphase
Microtubules pull sister chromatids apart, and each chromatid is now considered a chromosome
87
telophase
New nuclear envelopes form
Chromosomes uncoil
Briefly, cell binucleate
88
DNA to RNA
| Occurs in the nucleus
Transcription (occurs in nucleus)
89
RNA to protein
Translation (occurs in cytoplasm)
90
Micro RNA (miRNA)
regulation of gene expression
91
Messenger (mRNA), ribosomal (rRNA), and transfer (tRNA)
RNA involved in translation
92
codon
three nucleotides
93
coding strand: TGCAATC
template strand: ACGTTAG
| mRNA: UGCAAUC
94
transcription (key enzyme)
RNA polymerase
95
exons
code for protein
96
introns
do not code for protein
97
splicing
removing introns
98
review transcription and translation
yes
99
where does translation occur?
in ribosomes in cytoplasm
100
ribosomes
protein and ribosomal RNA (rRNA)
| With transfer RNA (tRNA), translate the message from mRNA into protein
101
tRNA
amino acid
tRNA
anticodon
(attached to codon)
102
Proteins made on rough ER and then...
transported to Golgi Apparatus
103
review slide 93 of "The Cell"
yes
