Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT biology > eukaryotic cells > Flashcards

eukaryotic cells Flashcards

1
Q

the function of the nucleus is to

A

contain and protect DNA, replication, transcription, splicing, and partial assembly of ribosome (2)

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

what surrounds the nucleus to separate the contents of the nucleus into distinct compartments?

A

nuclear envelope - which is compose of a lipid bilayer membrane

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

the genome is the sum total of

A

an organisms genetic information (chpt 4 notes)

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

the nuclear envelope contains pores that allow

A

passage of material in and out of the nucleus

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

the smaller molecules enter by what process through the nuclear envelope pores?

A

diffusion

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

the larger molecules enter by what process through the nuclear envelope pores?

A

they must have a nuclear localization sequence (basic amino acid sequence) so they can be translated on cytoplasmic ribosomes to be imported into the nucleus through specific transport mechanism

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

the nucleolus (contains no membranes) is a region within the nucleus that functions as a ribosome factory for

A

loops of DNA, RNA poly, rRNA, and protein components of the ribosome

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

the nucleolus is the site of?

A

transcription of rRNA by RNA poly I

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

the nucleolus is largest in cells that are producing?

A

large amount of protein - the increase of size reflects the increase of ribosome synthesis

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

the loops of DNA in nucleolus are used as a?

A

template for ribosomal RNA production

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

the mitochondria is the site of?

A

oxidative phosphorylation and produce ATP via the krebs cycle

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

the inner membrane of the mitochondria is the location of?

A

the electron transport chain and ATP synthase

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

the inner membrane of the mitochondria is impermeable to what type of substances?

A

polar substances

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

the folding of the inner membrane (cristae) increases what?

A

the surface area and allows for increased electron transport and ATP synthesis

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

the endosymbiotic theory suggests that mitochondria?

A

originated as independent unicellular organism living within larger cells because it possess their own genome that consists of single circular DNA molecules

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

mitochondria exhibit maternal inheritance which means that

A

if the female has a disease caused by an abnormality in her mitochondrial genome, her offspring will have that disease

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

the rough endoplasmic reticulum contains

A

a larger number of ribosomes bound to their surface

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

the ribosomes on the RER serve as the site of

A

protein synthesis for proteins that will enter the secretory pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

proteins synthesized on RER have three types of pathways:

A

1) will be secreted into the extracellular environment
2) will be intergral for plasma membrane proteins
3) will be in the membrane or interior of ER, golgi apparatus, of lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

signal sequence of a polypeptide is recognized by a signal recognition particle (SRP) which then binds to a

A

ribosome

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

the signal sequence is when proteins have a specific

A

amino acid sequence at their N-terminus

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

once a polypeptide binds to a ribosome via SRP, the RER has what?

A

SRP receptor that binds the ribosome-SRP complex to the cytoplasmic surface

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

once an ribosome-SPR complex binds to cytoplasmic surface, what happens?

A

translation then pushes polypeptide into ER lumen (page 181)

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

transmembrane domains are?

A

hydrophobic amino acid residues found on the interior of integral membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

transmembrane domains on integral membrane proteins allow for the protein to

A

pass through lipid bilayer membrane and not removed during translation and are threaded through the ER membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

targeting signals are needed for

A

protein traffic for proteins that need to end up elsewhere like the golgi, ER, or lysosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

localization signals are needed for

A

protein traffic for when proteins made in the cytoplasm need to be sent to an organelle that is not apart of the secretory path (e.g nucleus, mito, or peroxisomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

the three functions of the golgi apparatus are

A

1) modification of proteins made in the RER; especially important is the modification of oligosaccharide chains
2) sorting and sending proteins to the their correction destinations
3) synthesizes certain macromolecules, such as polysaccharides to be excreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

the vesicle traffic to and from the golgi apparatus is mostly

A

unidirectional

*retrograde traffic if proteins escape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the portion of the golgi nearest to the RER is

A

cis stack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

the portion of the golgi is the middle to the RER is

A

medial stack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

the portions of the golgi furthest from the RER is

A

trans stack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

the pathway of the vesicles from the ER is

A

cis to medial to trans, where each section has different enzymes where the vesicles are modified to be moved to the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

once the vesicles have left the golgi the are transported to the

A

cell surface and fuses with the cell membrane that the contents of the vesicles are released into the extracellular environment (exocytosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

constitutive secretory pathway is when vesicles are

A

immediately sent from the golgi to the cell surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

regulated secretory pathway is when vesicles are

A

release at specific times in a response from a change in the extracellular membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

SER function to

A

detoxification and glycogen breakdown in liver and steroid synthesis in gonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

RER function to

A

location of synthesis/modification of secretory, membrane-bound, and organelle proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

lysosomes function to

A

degradation of biological macromolecules by hydrolysis by acid hydrolases enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

lysosome proteins are made in the ____, then modified in the _____ to be released

A

RER and golgi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

lysosomes perform autophagy, which is

A

self-eating, when organelles have been damaged, they are degraded by the lysosome
ex: mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

lysosomes perform phagocytosis, which is

A

cell-eating, when lysosomes degrade large particulate matter by engulfing cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

lysosomes perform crinophagy, which is

A

lysosomal digestion of unneeded/excess secretory products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

after hydrolysis processes, the lysosomes will release

A

molecular building blocks into the cytoplasm for reuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

the enzyme lysosomes use for hydrolysis/degradtion is

A

acid hydrolases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

the environmental pH of lysosomes is around

A

5, so that the acid hydrolases can be active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

peroxisomes function to

A

metabolize lipids and toxins using H2O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

in the liver, peroxisomes help by

A

detoxification of drugs and chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

peroxisomes contain an enzyme called

A

catalase which converts H202 into H20 + 02

50
Q

peroxisomes protect the rest of the cell from

A

peroxides and oxygen radicals

51
Q

in the plasma membrane, integral membrane proteins are

A

embedded into the membrane by hydrophobic interactions - so that the hydrophilic head of the phospholipids are either on the top or bottom of it

52
Q

in the plasma membrane, the transmembrane domains are

A

membrane crossing regions, where the domains take up an entire section of the membrane

53
Q

in the plasma membrane, peripheral membrane proteins are

A

not embedded in the membrane but chill on the top or bottom of the hydrophilic head

54
Q

equation for molarity (M)

A

moles of solute divided by #liters of solution

55
Q

equation for molality (m)

A

moles of solute divided by #kg of solvent

56
Q

electrolytes are free ions in a solution that

A

conduct electricity

57
Q

strong electrolytes are solutes that

A

dissociate completely into solution

58
Q

weak electrolytes are solutes that

A

dissociate partially into solution

59
Q

van’t hoff factor (ionizability, i) states how many

A

ions one unit of a substance will produce in a solution
ex: NaCl = Na+ + Cl- i=2
CaCl2 = Ca2+ + 2Cl- i=3

60
Q

colligative properties are dependent on the

A

number of solute particles in the solution rather than the type of particle

61
Q

colligative properties include

A

vapor pressure depression
boiling point elevation
freezing point depression
diffusion/osmosis

62
Q

vapor pressure depression is when the pressure exerted by

A

gaseous phase of a liquid that evaporated from the exposed surface of a liquid

63
Q

in vapor pressure depression, the weaker the substance’s intermolecular forces,

A

the higher the vapor pressure thus easily evaporates

64
Q

in vapor pressure depression, volatile liquids are those that are

A

easily vaporized thus have high vapor pressure

65
Q

in vapor pressure depression, when a liquid contains a dissolved solute, the vapor pressure if effected by

A

solute molecules are attached to solvent molecules (anchors) thus more energy is require to enter gas phase
and adding more solute to solution will decrease its vapor pressure

66
Q

the boiling point of a liquid is defined as the

A

temperature at which the vapor pressure of the solution is equal to the atmospheric pressure over the solution

67
Q

in boiling point elevation, the more solute particles in the solution

A

the higher the BP

68
Q

in freezing point depression, presence of solute particles interfere with

A

the arrangement of solvent molecules thus the liquid will have a decreases freezing point

69
Q

diffusion is the tendency of

A

liquids and gases to fully occupy the available volume (high to low)

70
Q

osmosis is the tendency of

A

solvents to diffuse rather than solutes

71
Q

in osmosis, semipermeable membranes allow

A

water to pass but not other solute particles like sucrose

72
Q

isotonic environment of a cell is when

A

the solute concentration is the same on the inside and outside

73
Q

hypertonic environment of a cell is when

A

there are more total dissolved solutes than the cell (wrinkled cells)

74
Q

hypotonic environment of a cell is when

A

there are less total dissolved solutes than the cell (swollen cells)

75
Q

osmotic pressure is the pressure it would take to

A

stop osmosis from occuring

76
Q

passive transport is when any

A

thermodynamically favorable movement of solute across a membrane where no energy is required

77
Q

simple diffusion is when

A

diffusion of solute through a membrane with help from a protein

78
Q

facilitated diffusion is when

A

movement of solute across membrane, down a gradient, when the membrane itself is intrinsically impermeable to that solute
channel proteins and channel carriers

79
Q

facilitated channel proteins allow material that

A

cannot pass through the membrane by simple diffusion to flow through the plasma membrane down a concentration gradient

80
Q

voltage-gated ion channels open in response to

A

change in the electrical potential

81
Q

ligand-gated ion channels open in response to

A

binding of specific molecule (i.e. neurotransmitter)

82
Q

facilitated carrier proteins bind to molecules being

A

transported to one side of the membrane and then undergo a conformational change to move the molecule to the other side

83
Q

the facilitated carrier protein, uniports transport

A

only one molecules

84
Q

facilitated carrier protein, symports transport

A

two substances

85
Q

facilitated carrier protein, antiports transport

A

carry two substances in opposite direction of gradient

86
Q

eukaryotes do not contain pores in the membrane because

A

pores destroy the barrier function of the membrane and allow solutes in the cytoplasm to freely diffuse out of the cell

87
Q

active transport is the movement of

A

molecules through membrane against a gradient that requires energy and proteins

88
Q

in primary active transport the molecule being transported is

A

coupled to ATP hydrolysis

89
Q

in secondary active transport the molecule being transported is

A

not directly coupled to ATP hydrolysis but rather the ATP is used first to created a gradient, then the potential energy is used to drive the transport

90
Q

the sodium potassium pump is a

A

transmembrane protein in the plasma membrane that pumps 3 sodium (Na+) out of the cell and 2 potassium (K+) into the cell

91
Q

the purpose of 3 sodium out and 2 potassium in, is to

A

hydrolyze one ATP to drive the pumping of these ions against their gradients

92
Q

once sodium has been pumped out they cannot return because

A

the membrane is impermeable to sodium ions

93
Q

potassium leak channels allow for

A

potassium ions that have been pumped into the cell to leak out depending on concentration gradient

94
Q

resting membrane potential drives secondary active transport because

A

as K+ leak from the cell, the movement of positive charge out of the cell creates an electric potential across the membrane with a net negative charge on the inside of cell

95
Q

the main purposes of the sodium potassium ATPase (pump) is to

A

maintain osmotic balance between the cell’s inside and outside
establish the resting membrane potential
provide the sodium concentration gradient used to drive secondary active transport

96
Q

mnemonic: life evolved in the ocean, which has high concentrations of NaCl, thus the concentrations of

A

Na+ and Cl- are high outside the cell and low inside the cell

97
Q

exocytosis is the process to transport material

A

outside of a cell in which a vesicle in the cytoplasm fuses with membrane and the content of the vesicle expelled into extracellular space

98
Q

endocytosis is the process in which materials are

A

taken into the cell by invagination of a piece of membrane to form a vesicle (endosome)
*3 types of endocytosis

99
Q

the first type of endocytosis is, phagocytosis which is

A

cell eating where there is an uptake of large particulate matter into a phagocytic vescile, which later merges with a lysosome

100
Q

the second type of endocytosis is, pinocytosis which is

A

cell drinking where a nonspecific uptake of small molecules and extracellular fluid via invagination

101
Q

the third type of endocytosis is, receptor-mediated endocytosis which is

A

site of endocytosis is marked by pit coated with clathrin (inside) and with receptors that bind to specific molecules (outside)
ex: cholesterol in the blood where if they are not removed they build into the walls of the arteries

102
Q

cell surface receptors bind through what type of mechanism?

A

lock and key

103
Q

the key component for a receptor is termed a

A

ligand

104
Q

signal transduction is when

A

a ligand is binding to its receptor on the extracellular surface of the plasma membrane that triggers a response within the cell

105
Q

ligand-gate ion channels are

A

channels that open upon the binding of a particular neurotransmitter
ex: when Ach binds, the receptor has confirmational change to become a sodium channel resulting in massive influx of Na+ to depolarize to muscle cell to contract

106
Q

catalytic receptors are

A

enzymatic active sites on cytoplasmic side of the membrane

the main protein is kinase, which is an enzyme that binds phosphate groups to proteins

107
Q

G-protein-linked receptors

A

associated with an intracellular protein that binds and hydrolyses GTP. When GTP is bound, the protein is active, and can regulate the activity of adenylyl cyclase; this modifies the intracellular levels of the second messenger cAMP. When the GTP is hydrolyzed to GDP, the protein become inactive again

108
Q

what provides structural support via cell wall in bacteria, plants, and fungi?

A

cytoskeleton

109
Q

what are the three types of internal cytoskeleton in animal cells?

A

microtubules, intermediate filaments, and microfilaments

110
Q

what two globular proteins are microtubules made of?

A

alpha-tubulin and beta-tubulin that form alpha beta- tubulin dimer

111
Q

what can microtubules only elongate at one end?

A

one side of the microtubule is anchored to the microtubule organizing center (MTOC) located near the nucleus

112
Q

within each MTOC is a pair of centrioles, which duplicate themselves during?

A

cell division, duplicate and move to each end of the cell - in mitosis the microtubules radiating out from the centrioles attach to the replicated chromosomes and pull apart to be copied

113
Q

MTOC are essential for mitosis but centrioles are not because

A

plant cells lack centrioles but still undergo mitosis

experiments have removed centriole and still have cells undergo mitosis

114
Q

microfilaments are rods formed in the cytoplasm from polymerization of the globular protein?

A

actin

115
Q

microfilament are essential for what function of the cell?

A

gross movement of entire cell, such as pinching and dividing parent cell into two daughter cells during cell division
and ameoboid movement (cell flowing in one direction)

116
Q

tight junctions form seals between cells that prevent the

A

movement of substances across the cell layer

they are bands running all around the cells

117
Q

tight junctions are found where in the body?

A

between the epithelial cells lining the intestines and between the cells forming the capillaries in the brain (blood-brain barrier)

118
Q

desmosomes are used in epithelial cells in the skin to

A

tightly hold together cells but not forming a complete seal

119
Q

desmosomes are concise points around the cell which are anchored to the plasma membranes of two cells by the protein

A

keratin

120
Q

gap junctions are pore like connections between adjacent cells that allow two cells’ cytoplasms to mix to permit the exchange of

A

ions, amino acids, and carbohydrates

NOT polypeptides or organelles

121
Q

gap junctions are located where in the body?

A

smooth and cardiac muscles to allow membrane depolarization of an action potential to pass directly from one cell to another

122
Q

oncogenes are mutated genes that

A

cause cancer by converting normal cells into cancerous ones

MCAT biology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions