cell biology Flashcards
(102 cards)
1
Q
major tenants of cell theory
A
- all living things are composed of one or more cells
- all cells arise from preexsisting cells
- the cell is the most basic unit of life
2
Q
robert hooke contribution to bio
A
first compound microscope and examined first cells
3
Q
eukaryotic cells
A
have nucleus and membrane bound organelles
4
Q
what eukaryotic cells do not have nuclei?
A
RBCs
5
Q
function of nucleus
A
to store genetic information as chromosomes
6
Q
chromosomes
A
linear forms of DNA
7
Q
nuclear envelope
A
double memrbane sorrounding the nucleus with nuclear pores that allow rna and proteins into and out of the nucleus
8
Q
nucleolous
A
within the nucleus, synthesizes ribosomes
9
Q
glycolysis end products
A
2 net atp, 2 nadh , 2 pyruvate
10
Q
where does glycolysis occur
A
cytoplasm of prokaryotes and eukaryotes
11
Q
where does TCA cycle occur
A
mitochondrial matrix
12
Q
how is energy obtained by fats?
A
beta oxidation of fatty acids
13
Q
where does beta oxidation occur
A
mitochondrial matrix
14
Q
mitochondria
A
double memrbane organelle where majority of metabolism takes place. matrix is site of TCA cyckle and oxidative phosphorylation occurs in matrix and inner membrane
- self replicating organelle and has its own dna miDNA
15
Q
how is miDNA inherited?
A
maternally
16
Q
endosymbiotic theory
A
mitochondria derive from a primative cell capable of aerobic respiration
17
Q
lysosomes
A
garbage disposal of cell
waste enters via endocytosis and enzymes degrade waste
- thrive in acidic conditions
18
Q
endoplasmic reticulum
A
net like organelle connected to the nucleus. cisternae (flat structures)
rough ER
Smooth ER
19
Q
rough ER
A
covered in ribosomes
site of protein synthesis
20
Q
smooth ER
A
lipid metabolism (synthesis and breakdown) , break down of steriods, and detoxification
21
Q
golgi apparatus
A
modifies and packages proteins from the rough ER and targets them for their destination (largely for secretion)
22
Q
peroxisomes
A
peroxides accumulate here. major role in very long chain lipid break down and detoxification of ethanol/ alcohol
23
Q
cytoskeleton
A
composed of microtubules microfilaments and intermediate filaments
24
Q
cytoskeleton
A
composed of microtubules microfilaments and intermediate filamentsm
25
microfilaments
composed of two strands of actin and important to cell motality (movement) and exo/endocytosis
- also involved in muscle contraction
26
microtubules
slightly larger than microfilaments. and composed of dimers of proteins known as alpha and beta tubulinn
- maintain STRUCTURE of the cell
-CILLIA AND FLAGELLA
- make up mitotic spindles
27
what makes up the structure of cillia and flagella
microtubules
28
intermediate filaments
provide structural support and involved in CELL ADHESION
example: keratin
29
centrioles
cylindrical structures made of tubulin
- organizes mitotic spindle and important part of centromere
30
centromere
major microtubule organizing center of cell
- contains centrioles
31
flagella
made of microtubules
- tail like appendages that allow cells to move
- prokaryotes and eukaryotes
-powered by atp (in euk)
- powered by rotary motion in prok
32
cilia
made of microtubules
- small projections that help move substances along the surface (respiratory tract)
- euk and prok
33
9+2 structure
outer 9 rings of microtubules sorround inner ring of 2 microtubules
- structure of flagella and cilia
34
plasma membrane
seperates the cell from extracellular envirnment
- consists of lipids and proteins
- lipid bilayer membrane
35
what kind of lipids make up the plasma membrane?
phospholipids
- some sphingolipids
- waxes
36
major compoments of plasma membrane
lipids (phospholipids / sphingolipids)
cholesterol
proteins
carbohydrates
37
cholesterol plasma membrane function
promotes fluidity of membrane at low temperatures by preventing crystal structure formation and stability at high temperatures by preventing phospholipid movement
38
fluid mosaic model
liquid and protein components of the plasma membrane can move freely , phospholipids can shift sides (although energetically costly)
- small non polar diffusion
- larger molecules use transporters
39
lipid rafts
structures in the lipid membrane that contain high amounts of choelsterol and sphingomyleins
- contribute to fluidity and assist in signalling
40
embedded proteins
rooted in the interior of the membrane but do not span it
41
membrane associated proteins
have non-covalent interactions with structures on the membrane surface
42
transmembrane proteins
proteins that span the membrane including receptors and transport proteins
43
mitosis
asexual cellular replication
44
resting phase of cell cycle (G0)
no growth is occuring and no division , most fully differentiated cells are in g0 phase
45
interphase
cell prepares for division and takes up 90% of the cycle : major occurences are GROWTH and DNA REPLICATION
g1, s, g2
46
s phase
2nd stage on interphase were dna replication occurs
47
g1 check point
restriction point
- WHERE CELL COMMITS TO DIVISION
48
g2 checkpoint
checks for dna replication errors before division
49
cell division phases
prophase, metaphase, anaphase, telophase
50
prophase
point of mitosis where the cell prepares to divide
- condense DNA into distinct chromosomes
(sister chromatids bound at a core centromere)
- nuclear envelope dissolves and the mitotic spindle forms
51
kinetochore
assembles on centromere of chromosome and is where microtubule fibers bind for seperating sister chromatids
52
asters
microtubules that extends from centrosome to anchor it to the cell membrane
53
metaphase
chromosomes line up at the metaphase plate due to microtubules
- final checkpoint before division
- m checkpoint makes sure chromosomes are lined up correctly
54
anaphase
sister chromatids are pulled apart and pulled to opposite sides of the cell by shortening the microtubules
55
telophase
new nuclear envelope forms, nucleolous reappears and finally cytokinesis`
56
meiosis
sexual replication of cells
57
germ cells
sex cells
58
spermatogenesis
formation of male germ cells
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oogenesis
formation of female germ cells
60
end product of meiosis
4 haploid daughter cells --> gametes
61
end product of mitosis
2 diploid daughter cells (identical)
62
zygote
2 gametes fuse together to make a diploid cell
63
Meiosis 1
prophase 1 --> homologous chromosomes pair up and synapse to form tetrads (crossing over)
metaphase 1: homologous pairs line up at m plate
anaphase 1: homologous pairs are seperated (where cells become haploid )
telophase 1: 2 daughter cells with a chromosome in each
64
crossing over
when homologous pairs exchange genetic information to increase variance in prophase 1 of meiosis at the chiasmata
- produces recombinant dna
65
indepedent assortment
because the homolgous pairs are lined up randomly in metaphase1, there is random assortment of alleles
- will have one many combinations
66
what kind of cells undergo mitosis
somatic
67
commensalism
one organism benefits while the other recieves no benefit or harm
68
mutualism
both organisms benefit
69
parastitism
one organism benefits and one is harmed
70
anaerobes
bacteria that can not use oxygen (no aerobic respiration)
and oxygen is very toxic to them
71
aerotolerant anerobes
oxygen is nontoxic but they do not use oxygen
72
facultative anerobes
can use aerobic or nonaerobic respiration
73
where would anerobes be found in a test tube? aerobes>
aerobes: top
anaerobes: bottom
74
bacteria structure
prokaryotes
all have cell walls and membranes
no membrane bound organelles
75
what is the bacterial cell wall made of
peptidoglycan
76
gram staining
tests for thickness of bacterial cell wall
g + --> blue and thick cell wall of peptidoglycan
g - --> thin cell wall and has lpl , stains pink
77
gram stain process
primary stain (CV)
mordant (iodine)
alc wash
counterstain (safranin)
78
what makes gram negative bacteria toxic
lipopolysaccharide in membrane induces inflammatory response and innate immune system
79
where does aerobic respiration occur in aerobic bacteria
cell membrane
80
prokaryotic ribosome
30s and 50s
70s total
- often target of antibiotics
81
eukaryotic ribosome
40s and 60s
80s total
82
how do bacterial flagella work
they use a rotary motion powered by a proton graident
- flagella made of flagellin
83
chemotaxis
movement in response to a chemical signal
84
where does bacteria store dna
in the nucleoid region as a singular circuilar chromosome
85
T/F eukaryotes and prokaryotes can carry out transcription and translation at the same time
false. only bacteria can
86
plasmid
small circular pieces of DNA not part of essential dna
- contains advantages and important in antibiotic resistnace
- code for virulence factors
87
binary fission
cell division process for bacteria
1. replication
2. segregation and growth of new cell
3. seperation into identical daughter cells
88
bacterial growth curve
lag (infection. no growth)
log (exponential growth)
stationary (growth = death)
death (growth < death)
89
horizontal gene transfer
ways that bacteria increases genetic variation and mutations/ resistance
1. transformation
2. transduction
3. conjugation
90
horizontal gene transfer
ways that bacteria increases genetic variation and mutations/ resistance
1. transformation
2. transduction
3. conjugationt
91
bacterial transformation
horizontal gene tranfer that involves abosrbing sorrounding genetic information
92
bacterial transduction
virus mediated gene transfer where a bacteriophage infects bacteria and incorporates new dna into genome
93
bacterial conjugation
transfer of a plasmid from a bridge (sex) between cells using a pilus
94
viruses
obligate intracellular pathogens that require host to replicate
have genetic material and a protein covering known as capsid
- can be dna or rna. never both
95
viron
fully assembled infectious virus
96
negative sense virus
virus with rna that contains complimentary rna to mrna , rna must be synthesized by rna replicase`
97
positive sense virus
rna virus that contains viral mrna that is integrated
98
retrovirus
single strand rna virus that has enzyme reverse transcriptase to synthesize dna from their rna and incorporate its dna into host genome
99
lysogenic cycle
viral life cycle where viral genetic info is integrated into the host (prophage) and waits for ideal conditions before lysing and spreading genetic info to neighboring cells
100
lytic cycle
viral life cycle where virus infects host with viral dna and the cell lyses and spreads
101
prions
infectious misformed proteins
102
viroids
small infectious plant particles that can silence gene expression
