Ib bio > unit 8 > Flashcards

unit 8 Flashcards

(84 cards)

Study These Flashcards
1
Q

what is the endosymbiotic theory

A

a large prokaryote consumed a small prokaryote but didn’t digest it, it just stayed inside and made energy for the larger one and the larger one provided nutrients. the small prokaryote became the mitochondria of the future eukaryote. same for chloroplast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 pieces of evidence of the endosymbiotic theory

A
  1. both organellse have double membrane- vesicle from larger prokaryote became outer membrane
  2. mitochondria and chloroplasts have their own DNA. codon table is different
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

examples of single cell eukaryotes

A

algae, yeast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is differentiation

A

cells become different kinds but still have same DNA. allows cells to specialize in their function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

advantages of multicellularity

A

longer survival, guaranteed survival(stem cells), speciation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

single cell advantages

A

fast reproduction, dont need many nutrients, can live inside other things

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

parts of phospholipid bilayer

A

hydrophilic phosphate head, hydrophobic lipid tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are saturated fatty acids

A

long chain of carbons, single bond, surrounded by hydrogens
-are rigid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what temp is better for cells with saturated fatty acids

A

high because they can withstand it
can freeze at low temps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are unsaturated fatty acids

A

double bonds, bended
-fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what temp are more cells with unsaturated fatty acids at

A

low because it wont freeze and break
melts at high temperatures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is cholesterol

A

a steriod- 4 rings of carbon, very non polar, lipid, has hydroxyl
fits well into cell membrane-carbon around tail, OH around head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does cholesterol affect membrane fluidity

A

prevents saturated fatty acids from getting close together to increase fluidity, holds unsaturated fatty acids from moving to increase ridgidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

function of membrane fluidity

A

make vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how are vesicles formed

A

membrane pinches around what it needs to carry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

role of protein clathrin

A

is 3 pronged and pairs with others to form lattice around vesicle for better structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how do vesicles do exocytosis or endocytosis

A

by fusing with membrane of other molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

examples of cell needing to do endocytosis

A
  1. single celled organisms
  2. absorption of anitbodies into baby while in womb
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

examples if exocytosis

A
  1. single cell organisms removing waste
  2. propulsion by removing water quickly
  3. rough er to golgi to vesicle to carry proteins out(attached ribosomes are for other cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is a gated ion channel

A

membrane protein that is a channel-no energy required
-facilitated diffusion
-channel not always open(gated)
-usually let ions in and out(NA and K)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are neurotransmitters

A

carry signals across cleft and opens channel to continue signal being sent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is acetylcholine

A

a neurotransmitter that transmits signlas from neuron to muscle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are nicotine acetylcholine receptors

A

where acetylcholine binds to
where nictoine binds to brain cells to produce dopamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a voltage change

A

when sodium and potassium channels open because of movement of charge(action potential) from back and forth movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what are active transporters
types of membrane proteins for active transport-pump proteins -can move 2 types of molecules in opposite directions -use atp
26
example of active transporter
sodium potassium pump in neurons -Na out, K in -creates resting potential of more sodium out -concentration gradient
27
what does indirect active transport mean
when a pump protein and transporter molecule is involved
28
example of indirect active transport
Sodium dependent glucose co transporter -when sodium flows down concentration gradient through cotransporter, it can bring glucose with it regardless of the concentration of glucose -sodium originally used active transport in pump
29
examples of what the sodium-dependent glucose transporter is used for
-how most cells receive glucose -how the small intestine gets glucose into blood stream by going against the concentration gradient -how kidneys regulate blood glucose in blood and urine
30
what are cell adhesion molecules used for
cells sticking to other cells
31
examples of CAMS being used
tissues are from same type of cell sticking together -organs are made of different tissues- different cams -creates multicellularity
32
how do membranes affect reactions
membranes allow separate chemical reactions and higher concentrations of chemicals for faster reactions
33
why does nucleus have double membrane
from vesicles forming spherical shaoe -we think this because of openings(pores) between double membrane
34
benefits of pores in nucleus membrane
-entry and exiting of RNA after transcription for translation(ribosomal rna made in nucleus) faster than vesicles -easier dissolvement during mitosis
35
why does rough ER have single membrane
it makes it easy for ribosomes to attach
36
process of protein going from ER to golgi
bound ribosomes are packaged into vesicle-possible because of fluidity vesicle fuses with golgi membrane for protein to enter and be modified vesicles made for movement between each tube protein is repackaged into vesicle and sent out of cell by exocytosis
37
what do free ribosomes do
make proteins for cell itself
38
differences in cisternae between ER and Golgi
ER has connected tubes for movement, golgi has separated for benefits of compartmentalization
39
examples of golgi modifications
cut protein, add amino acid, remove amino acid
40
example of organ with lot of golgi and rough er
pancreas because it makes hormones and proteins in enzymes
41
what is the baseline of water potential compared to
water at standard pressure and temperature(0 water potential)
42
what is water potential
same thing as potential energy movement of high to low water potential
43
what are cells max water potential without bursting
0 numbers usually go from negative to more negative
44
water potential formula
solute potential(psi s)+pressure potential(psi p)=water potential(psi)
45
affects of pressure on water potential
can be above 0 if above atmospheric pressure -high can force water out -low can allow water in
46
cell wall impact on water potential
cell walls can change and control pressure within cell
47
hypotonic solutions water potential vs cell
hypotonic solutions have higher water potential than cell -increases solute potential by diluting cell and increasing pressure in cells with wall because area stays same.
48
what are protein receptors
receive signals that bind to receptor send signals into cell in different ways to change cell
49
what is a ligand
molecules attaching to protein receptor -specific stays the same and stays attached for as long as possible
50
what is quorum sensing
bacteria looking to see if there is enough bacteria around to start response by looking for amount of signals
51
examples of quorum sensing
1. biofilm: creating film to capture nutrients 2. bioluminescence: producing light to camoflauge or attract
52
distinguish between categories of cell signals
1. hormones: made by glands, travel through bloodstream, last for long time, widespread effects 2. neurotransmitters:carry signal across synapse neuron to neuron, short distance, short lasting effects, narrow area affected 3. cytokines: travel through bloodstream, short distances, long or short term effects, usually in immunse system(interferons) 4. calcium ions: mainly neurons, assist in muscle contraction 5. pheremones
53
what is the usual end goal of signals
gene expression-turning off or on genes
54
2 ways of cell signalling
signal transduction pathway or signal itself can bind to receptor within cell and then carry out gene expression
55
how do sterioids carry signal
bind to receptor inside cell once it binds, new molecule can turn off or on genes
56
2 examples of hormonses/sterioids that go inside cell to do gene expression
1. estrogen: in women it binds within cells of hypothalamus. new molecule turns on gene that makes another hormon called GnRH. that hormone triggers release of LH and FSH at different times. 2. Progesterone: when its made by ovaries, it enters cells in uterus and binds to receptor inside. When it binds, it makes cell signal that tells uterus cells to start dividing to buildup uterus lining.
57
reasons for cell proliferation
1. growth in multicelluar organisms -animals do this for part of life, plants do for entire life 2. replace old cells, dead cells, or damaged cells -cells are often programmed to die-skin cells every day in humans
58
what are stem cells
self repairing cells
59
what are meristems
constantly dividing cells in plants
60
steroid vs hormone
steriods are classified off structure, hormones off function
61
cell cycle summary
interphase: everything it does when not dividing to get ready for mitosis mitosis: make 2 identical nuclei cytokinesis: splits cell
62
3 steps of interphase
1.G1: doing life functions, growing G= gap 2. S-Synthesis: making DNA through replication so it can be evenly split 3. G2: growing more because it is about to split and split organelles -mitochondria does all this within itself
63
what is G0
when cells stay in the G1 phase forever-most of our cells
64
what proteins control cell cycle
cyclins
65
how does cyclin control cell cycle
when cyclins get made, they bind to kinases for phosphrylation, signaln transduction pathway, and gene expression. genes make enzymes or molecules needed for cell cycle. -has threshold for number of cyclins
66
what is a mutation
any change in dna causes problems when in gene
67
what are pro-oncogens
genes that make cyclins and kinases
68
what are oncogenes
mutated proto-oncogenes -causes super active cyclins or kinases -messes up cell cycle and causes cancer
69
what is a tumor
bundle of pointless cells-one place
70
what are tumor suppresor genes
evolutionary traint that check syclins, kinases, and DNA to fight cancer -more dangerous if mutated
71
what is apoptosis
progammed cell death- checked by tumor suppressors
72
what is the primary tumor
original tumor that begins dividing
73
what is a malignant tumor
a tumor that got into bloodstream and spread
74
what is metastasis
process of cancer spreading
75
secondary tumors
tumors that have spread
76
what does diagnosis come from
number of cells going through mitosis
77
# ** what is the mitotic index
number of cells in mitosis/ number of total cells -higher=more likely cancerous
78
what are G proteins
not membrane protein,just attached to them
79
how are g proteins activated
receptor receives signal and changes shape which activates it
80
what happens after g protein is activated
it breaks into many pieces and scatters throughout cells -causes many changes at once, many signals being sent
81
examples of g protein activation
response to hormones response to light response to smell epinephrine receptors
82
what happens when epinephrine activates g protein
another progtein called adenylyl cyclase is activated. adenylyl changes ATP into Cyclic AMP(secondary messenger) -can cause liver breaking down glycogen into glucose causing it to be released into bloodstream
83
what is a membrane kinase
special kind of enzyme thst takes phosphate from ATP to give to something else- called phosphorylation
84
Ib bio
flashcards
Decks in class (15)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions