The Cell Flashcards
1
Q
what is a cell?
A
the structural & functional unit of life
2
Q
what are organelles?
A
small structures within cells with specialized functions - depending on their shape and form
3
Q
cytology
A
the study of cell structure and function
4
Q
what are the three distinct features of a human cell?
A
- the plasma membrane
- the cytoplasm
- the nucleus
5
Q
*callback question
what is the hiearchy of organization?
A
- atom
- molecule/compound
- organelles
- cells
- tissue
- organ
- organ systems
- organism
6
Q
plasma membrane
A
flexible yet sturdy barrier that surrounds and contains the cytoplasm of the cell
7
Q
what is the plasma membrane made of?
A
- composed of a bilayer of lipids w/ protein molecules dispensed in it
8
Q
describe the lipid molecules within the plasma membrane.
A
- created with hydroPHILIC heads & hydroPHOBIC tails
- creation of both nonpolar & polar regions aka amphipathic molecules
- makes up of 75% of the membrane
9
Q
what else is the plasma membrane made of besides phospholipids?
A
- Cholesterol cells: make up of 20% [helps maintain the membrane and keeps integrity - glue of membrane]
- Glycoproteins/glycolipids: make up of 5% [energy source & cell recognition]
10
Q
what are membrane proteins?
A
proteins that allow communication with the environment
11
Q
how many types of membrane proteins do we have?
A
2; peripheral & integral
- peripheral: temporarily attached to membrane - simple makers for the cell
- integral: permanently attached to membrane
12
Q
what are the functions of the membrane proteins? (hint: there’s 6)
A
- transport
- receptors for signal transduction
- attachment to cytoskeleton & extracellular matrix
- enzymatic activity
- intercellular joining
- cell-cell recognition
13
Q
what are the integral proteins?
A
- Ion Channels
- carriers
- receptors
- glycoproteins/cell identity markers
14
Q
what are the peripheral membrane proteins?
A
- enzyme (can also be INTEGRAL)
- linkers (can also be INTEGRAL)
15
Q
transport - membrane protein
A
provides channel that is selective for specific solute
16
Q
receptor: signal transduction - membrane protein
A
becomes a binding site for specific chemical messengers (hormones); they can change shape
17
Q
cytoskeleton attachment + extracellular matrix - membrane protein
A
anchoring of membrane proteins; helps maintain cell shape
18
Q
enzymatic activity - membrane proteins
A
help catalyze steps within cell processes; metabolism
19
Q
Ion Channel
A
- integral protein
- specific pore allowing flow of specific ions in/out of membrane
20
Q
Carriers
A
- integral protein
- transportation of spec. substances and undergo shape changes
21
Q
Receptors
A
recognition of specific ion/molecules, ligands which can alter the cell’s function
22
Q
Enzymes
A
- integral & peripheral proteins
- catalyzes reaction inside or outside of the cell depending on active sites
23
Q
Linkers
A
- integral and peripheral protein
- maintains stability and shape of the cell
24
Q
what are cell junctions?
A
cellular structures consisting of multiprotein complexes–providing contact or adhesion between cells
25
what kind of cell junctions do we have?
- desmosomes
- tight junctions
- gap junctions
26
tight junctions
junction that forms a continuous seal around cells
- similar to a zipper :) (it is impermeable)
27
desmosomes
junction that binds adjacent cells together; helps in forming internal tension - reducing network of fibers
- similar to buttons :)
28
gap junctions
junctions that aid in communcation and allows ions and small molecules to pass
29
intracellular fluid
the fluid found inside cells
30
cytosol
a complex mixture of substances (organelles, nutrients. etc.) dissolved in water (cytoplasm)
31
extracellular fluid
denotes all the body fluid that is outside of the cells
32
what are the two divisions of the ECF?
- blood plasma
- interstitial fluid
33
blood plasma
holds the blood cells in whole blood in suspension
34
interstitial fluid
found within the interstitial spaces - tissue spaces; solution that bathes and surrounds the cells of multicellular animals
35
plasma membranes are _______________
selectively permeable; some molecules pass through easily--some do not
36
what are the two ways that substances can cross through the membrane?
- passive processes
- active processes
37
concentration gradient
the difference in the concentration of a chemical between one side of the plasma membrane
38
electrical gradient
the difference in concentration of ions between one side of the plasma membrane and the other
39
what are the passive processes?
- no ATP required
- moving down a concentration gradient
- typical within small molecules only
1. filtration
2. simple diffusion
3. facilitated diffusion
4. osmosis
40
filtration
- passive process
- movement of water and solute molecules across the cell membrane due to hydrostatic membrane (generated by cardiovascular sys.)
- typical within the kidneys
41
simple diffusion
net movement of substances from an area of high concentration to an area of low concentration until we reach equilibrium
- example: dropping ink into water and its diffusion!
42
what is diffusion influenced by?
- steepness of concentration gradient
- temperature
- mass of diffusion substance
- surface area
- diffusion distance
43
facilitated diffusion
- passive process
- this specific diffusion is aided by membrane-transport channels and can bind to carrier proteins
- carrier-mediated transport
- ion-channel mediated transport
44
carrier-mediated transport - facilitated diffusion
- usage of carrier proteins
- transports specific polar molecules (ex. sugars, amino acids) that are too big for the channels
45
ion-channel-mediated - facilitated diffusion
- selectively transports ions or water
- leakage channels: always open
- gated channels: controlled by chemical or electrical signals
46
osmosis
- passive process
- net movement of a solvent through a selectively permeable membrane from an area of high dilution to an area of low dilution
- typical solvent: water
47
isotonic solution
cells retain their normal size--equal concentration gradients both inside and outside (same osmolarity)
48
hypertonic solution
cells lose water; begin to shrink or otherwise as known as crenation - the concentration OUTSIDE of the cell has a higher concentration of solutes
49
hypotonic solution
cells begin to absorb more water; cells will bloat or burst *hemolysis
- concentration INSIDE the cell has a higher concentration of solutes
50
what are the active processes?
- primary active transport (small molecules)
- secondary active transport (small molecules)
- vesicular transport (large molecules)
51
primary active transport
- involves the direct influence of ATP in regards to mass transport
52
secondary active transport
required energy indirectly from ionic gradients created from primary active transport
UNIPORTERS - transportation of one substance (one direction)
COTRANSPORTERS: (transport of two types of substances)
- symport pumps: same direction
- antiport pumps: opposite direction
53
vesicular transport
transportation usage of vesicles enclosing material
54
what are the types of vesicular transport?
- exocytosis
- endocytosis
- endo-phagocytosis
- endo-pinocytosis
- endo-receptor-mediated RME
- exo-transcytosis
55
exocytosis
transporting material OUT of the cell
56
endocytosis
transporting material INTO the cell
57
endo-phagocytosis
cell ingesting solid materials or engulfing materials using pseudopods + combined with lysosomes to kill bacteria WITHIN the cell
58
endo-pinocytosis
ingestion of extracellular fluid "cell drinking"
59
endo-recepter-mediated-RME
cells begin to absorb metabolites, hormones, and proteins
60
exo-transcytosis
combination between endocytosis and exocytosis to move substances from Point A to Point B
61
cytoplasm
- functions as a transport medium
- aids in suspension of intercellular substances
62
what is the cytoplasm made of?
- cytosol
- organelles
- inclusions
63
cytoskeleton
elaborate series of rods throughout cytosol; proteins link rods to other cell structure
64
what are the three types of rods found in the cytoskeleton?
- microtubules
- microfilaments
- intermediate filaments
65
microfilaments
- aid in mechanical support
- dynamic strands of ACTIN
- cell motility, shape changes, endo & exo
66
microtubules
- largest element within the cytoskeleton
- composed of protein subunits: TUBULIN
67
intermediate filaments
- tough, insoluble protein fibers similar to woven ropes
- acts as anchor and resists pulling forces
- TETRAMER subunits
68
centrosomes
maintains chromosome number and controls organization of microtubules
69
centrioles
helps with cell division and organizes the mitotic spindle in cell division
70
cilia
cellular extension that has a fixed location--moves substances across cell surfaces
71
flagella
mobile cellular extension--ex. tail of sperm
72
microvilli
minute, fingerlike extensions on plasma membrane
- increases surface area for absorption and secretion
- core of ACTIN filaments for stiffening
73
ribosomes
workbench of protein synthesis
74
free ribosomes
free-floating ribosomes that make soluble proteins (found in cytosol and organelles)
75
membrane-bound ribosomes
found on the Rough ER; synthesizes proteins and then can be transported throughout or outside the cell
76
what makes up a complete ribosome?
- large subunit
- small subunit
77
endoplasmic reticulum (ER)
- detoxifies chemicals
- transports substances
- releases calcium ions for muscle contractions
78
Rough ER
synthesizes secretory proteins
79
Smooth ER
- lipid metabolism
- chemical detoxification
cholesterol + steroid synthesis
80
golgi apparatus (GA)
stacked and flattened membranous sacs
- the cell's personal UPS
- modifies, concentrates, packages, etc,, from Rough ER
- proteins packaged differently depending on location
- entry - CIS face
- exit - TRANS face
81
lysosomes
- the cell's personal trash can
- digestion of ingested bacteria, viruses, toxins
- process of autolysis
- breaks down bone to release calcium ions
82
primary lysosomes
non-active organelles
- waiting to receive endocytosed material
83
secondary lysosomes
- active organelle
- formed when primary lysosomes fuse with endocytic vesicles
84
peroxisomes
detoxifies harmful toxic substances; neutralizes free radicals
85
mitochondria
POWERHOUSE OF THE CELL!!!
- oxidizes substrates turning them into energy
- synthesizes ATP - energy
- has its own DNA (mtDNA) - maternal inheritance of DNA
86
Nucleus
largest organelle; blueprint for nearly all cellular problems
- responds to signals; dictates kinds and amounts of protein synthesized
- creation of RNA: mRNA & tRNA
87
nuclear envelope
- membrane bilayer structure that continues with ER
- has nuclear pores: controls transport
88
nucleolus
- creates ribosomes
- dark-staining spherical bodies
89
DNA
- double helix shape; supercoiled around histone proteins
- found within nucleus
90
how many chromosomes do we have?
- 23 pairs of chromosomes
- 46 chromosomes in total (diploid): full human genetic genome
- 22 autosomes + last pair sex chromosome (23)
91
karyotype
display of full set of 46 chromosomes that are stained, photographed, and arranged
92
what are the bases in DNA?
A - adenine
T - thymine
C -cytosine
G - guanine
*in RNA, thymine is replaced with U (uracil)
triplets (ATG, CTA, TTC...) - form genetic library
93
genomics
the study of the genome and its relationship to body function
94
mRNA
carries the instructions for building a polypeptide, from gene in DNA to ribosomes in cytoplasm
95
tRNA
binds to amino acids and pairs with bases of codons of mRNA at ribosome - 1st step of protein synthesis
96
rRNA
structural component of ribosomes that help translate message from mRNA
97
transcription
(in nucleus)
- dna into mRNA
98
translation
(in cytoplasm)
- tRNA to ribosome
99
what are genes composed of?
- exons: code for amino acids
- introns: noncoding segments
100
mitosis
division of nucleus
101
what are the stages of mitosis?
- interphase
- prophase
- metaphase
- anaphase
- telophase
- cytokinesis: division of cytoplasm - cleavage furrow
