BIO - EXAM 2 Flashcards
(153 cards)
1
Q
Contractile vacuoles
A
prevent cells from bursting as a result of the influx of excess water.
2
Q
lysosomes
A
all answers are correct; destroy harmful bacteria engulfed by cells, merge with food vacuoles to expose them to lysosomal enzymes, help to digest worn-out or damaged organelles.
3
Q
the golgi apparatus
A
stores, modifies, and packages proteins and lipids
4
Q
the endosymbiosis hypothesis proposes that
A
a proto-eukaryotic cell engulfed a smaller cell, which then survived inside the larger cell to the benefit of both
5
Q
the idea that all living things are composed of cells and that cells arise from pre-existing cells defines
A
the cell theory
6
Q
the nuclear envelope differs from a cell membrane in that the nuclear envelope
A
is made of a double phospholipid bilayer
7
Q
the nucleoid region of a prokaryotic cell
A
contains the cell’s DNA
8
Q
which answer lists the two type of electron microscopes discussed in class
A
scanning and transmission
9
Q
which of the following is almost never observed in plant cells
A
centrioles
10
Q
while maintaining the same shape, as cell size increases
A
the volume increases faster than the surface area
11
Q
which part of the mitochondrion shown enhances its ability to produce ATP by increasing the surface area of a mitochondrial membrane
A
structure D - the crevices or folds
12
Q
melanocytes in the skin to have a higher than usual number of
A
ribosomes
13
Q
describe the process by which a cell creates and releases a functional polypeptide to the external environment via the endomembrane system. be sure to explain the correct order and action of the following components: cytoplasm; endoplasmic reticulum; golgi apparatus; nucleus; ER-vesicle, Golgi-vesicle
A
- Nucleus. the nucleus transcribes RNA
- cytoplasm and endoplasmic reticulum. the RNA then goes to the cytoplasm and endoplasmic reticulum to translate into polypeptide.
RER: proteins enter
SER: lipids made - the ER-Vesicle then transfers the hald modified-polypeptide to the golgi apparatus
- golgi apparatus - modifies the polypeptide and then the golgi - vesicle merge with the plasma membrane to be released or remain in the cell to serve a certain purpose
14
Q
an animal cell will shrivel up via osmosis when placed in a ———- solution
A
hypertonic
15
Q
diffusion is
A
the movement of solute particles from an area of high concentration to low concentration
16
Q
glucose molecules provide energy to power the swimming motion of sperm. in this example, the sperm are changing
A
potential energy into kinetic energy
17
Q
most of a cell’s enzymes are
A
proteins
18
Q
osmosis is
A
diffusion of water molecules from an area of low solute concentration to an area of high solute concentration
19
Q
the mechanism by which human cells obtain LDL cholesterol particles form intercellular fluid is
A
receptor mediated enocytosis
20
Q
the transfer of a phosphate group to a molecule or compound is called
A
phosphorylation
21
Q
when an enzyme catalyzes a biochemical reaction it
A
lowers the activation energy of the reaction
21
Q
which is NOT an example of cellular active transport
A
osmosis
21
Q
which of the following is NOT an example of cellular passive transport
A
movement of ions via protein pumps
21
Q
which part of the ATP molecule breaks free of the rest when an ATP molecule is used for energy
A
part d - the last phosphate
22
which figure depicts an animal cell placed in a solution hypotonic to the cell
cell A - exploding from both ends
23
a major function of glycoproteins and glycolipids in the cell membrane is to
allow for cell recognition
24
according to _________, energy cannot be created or destoryed
the first law of thermodynamics
25
what is the basic difference between exergonic and endergonic reactions
exergonic reactions release energy; endergonic reactions absorb it
26
by-products of cellular respiration include
carbon dioxide and water
27
cyanide differs from dinitrophenol in that
cyanide is an electron transport blocker, while dinitrophenol makes the membrane of the mitochondrion leaky to H+ ions
28
bacteria that are unable to survive in the presence of oxygen are called
obligate anaerobes
29
as a result of glycolysis there is a net gain of _____ ATPS
2
30
during cellular respiration, NADH
delivers its electron load to the first electron carrier molecule
31
during chemiosmosis
ATP is synthesized when H+ ions move through a channel inATP synthase
32
the overall equation for the cellullar respiration of glucose is
C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy
33
the processes of photosynthesis and cellular respiration are complementary. during these energy conversion, some energy is
lost in the form of heat
34
which H+ ion has just passed through the inner mitochondrial membrane by diffusion
hydrogen ion D - going through a flask shaped memebrane, last one.
35
which step of the citric acid cycle requires both NAD+ and ADP as reactants
step 3
36
chloroplasts contain disklike membranous sacs arranges in stacks called
grana
37
Mitochondria transfer ____________ energy from ____________ to ATP; chloroplasts transform _____________ energy into the chemical energy to ATP
chemical..... food........ light
38
in this drawing of a chloroplast, which structure represents the thylakoid membrane
structure c - the singular sacs (indivdual pancakes)
39
which of the following options lists the stages in cellular respiration in the correct order
glycolysis, the critic acid cycle, and oxidative phosphorylation
40
yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are
facultative anaerobes
41
early discoveries
mid 1600s - Robert Hooke, observed and described cells in cork, later 1600s - Anthony Van Leeuwenhoek, observed sperm, microorganisms, 1820s- Robert Brown, observed and named nucleus in plant cells, 1850 - Rudolf Virchow, proposed that all cells come from existing cells
42
cell theory
1) cell is the smallest unit of life - survive, reproduce, metabolism, respond
2) all organisms consist of 1 or more cells
3) all cells come form pre-existing cells
43
magnification
increase in the apparent size of an object
43
resolution
measure of the clarity of an image
44
light microscope
simple or compound
45
electron microscopes
transmissions EM or scanning EM
46
light microscopy (explained)
wavelengths of light = 400 - 750 nm
if object <1/2 wavelength, it will not be visible, resolution 200nm, magnification 1,000 x
47
electron microscopy (explained)
uses streams of accelerated electrons focused by magnets, resolution 2 nm (or less), magnification 100,000 x (or more)
48
minimum size
determined by the total size of all the molecules required for cellular activity
49
maximum size
limited by the need for sufficient surface area to volume ratio to carry out function
50
as cells get larger...
surface area and volume both increase
but volumes increases more than surface area
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total volume
L x W x H
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total surface area
L x W x # of sides
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surface to volume ration
SA/V
54
increase sa/v ratio by
changing shape from round to long, narrow + folded
55
all cells have
plasma membrane, DNA, cytoplasm w/ ribosomes
56
plasma membrane
structure: phospholipid bilayer with embedded proteins, glycolipids, glycoproteins, sterols
function: isolates cell contents, controls what gets in and out of the cell, and receives signals
57
selectively permeable
lipid - soluble molecules pass through (small non-polar molecules, fat soluble molecules)
lipid - non-soluble molecules do not pass through
(large polar molecules, ions, water)
58
all cells have genetic material as DNA
Eukaryotes: DNA is within a membrane (nucleus)
Prokaryotes: no membrane around the DNA - region is called nucleoid
59
cytoplasm with ribosomes
cytoplasm - fluid area inside outer plasma membrane and outside DNA region
60
prokaryotic cells
archaea and eubacteria, generally the smallest, simplest cells, prokaryotic cells do NOT have: nucleus and membrane bound organelles
61
what are in prokaryotic cells
plasma membrane, nucleiod, cytoplasm with ribosomes, cell wall, capsule, pili, flagella
62
archaea
inhabitat hostile enviornments
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protein lattice
anchored to outer membrane to help withstand extreme conditions
64
eukaryotic cells
usually larger than prokaryotic cells, distinguished by a true nucleus, contain both membranes and non-membranous organelle
65
what are in eukaryotic cells
nucleus, ribosomes, endomembrane system: endoplasmic reticulum, golgi apparatus, vesicles. mitochondria, cytoskeleton
66
animal cells lack:
cell wall, central vacuole, chloroplasts
67
cell wall
function: provides support and protection
- never found in animal cells
- present in plant, bacterial, fungus, some protists
structure: wraps around the plasma membrane. made of cellulose and other polysaccharides
68
plant cells lack:
centrioles, lysosomes, and often flagella
69
extracellular matrix
glycoprotein, binds animal tissues
70
tight junctions
seal tissue cells so no leaking. ex:gut
71
anchoring junctions
also called desmosome, allow continual stretching, ex: skin and heart
72
gap junctions
connect cytoplasm between cells, allows rapid transfer of substances, ex: heart
73
nucleus
1)manufactoring
2) structure: double layer membranes with pores
3)isolate the DNA, controls what get in/out
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ribosomes
1)manufacturing
2) structure: two subunits that come together
3) function: makes proteins, takes mRNA --> turn into a protein
75
rough ER
1)manufacturing
2)structure: membrane system w/ ribosomes attached
3) function: make and modify proteins, shipped to golgi apparatus
76
smooth ER
1) manufactoring
2) structure: no ribosomes
3) function: makes lipids, shipped to golgi apparatus
77
golgi apparatus
1) manufacturing
2) structure: stack of flattened membrane sacs with no ribosomes
3) function: receives proteins and lipids from the ER, sends out to the destination
78
Lysosomes (in animals only)
1) Breakdown
2) structure: contains sacs enzymes
3) function: cell "eating" used for digestion, recycles damaged organelles, breaks bacteria in white blood cells
79
central vacuole
1) breakdown
2) structure: in plant cells
3) function: has enzymes that break down waster. storage function, food, ions
80
contractile vacuole
1) breakdown
2) structure: some protists have them
3) function: pump excess water out of cell
81
peroxisomes
1)breakdown
2) structure: smaller but similar to lysosomes
3) function: hydrogen peroxides is broken down to H20+O2
82
mitochondria
1) energy processing
2) structure: outer membrane, inner membrane, inter membrane space, folds called cristae, matrix - DNA and ribosomes
3) function: produces ATP (energy currency) for the cell from food - cellular respiration
83
chloroplasts (in plants only)
1) energy processing
2) structure: inner and outer membranes, granum (stacks of membranes), stroma - fluid to surround granum, with photo - synthetic pigments
3) photosynthesis, make sugar from using solar energy
extra - also has mitochondria to break down sugar to ATP, makes their own food - but still need to break down to energy
84
Cytoskeleton
microfilament, intermediate filament, microtubule
85
microfilament
1) support, movement, and communication
2) structure: smallest components, composed of the protein actin
3) cell movement
86
intermediate filament
1) support, movement, and communication
2) structure: intermediate size, not hollow, only found in animal cells
3) structure: holds cells together and maintain shape
87
microtubule
1) support, movement, and communication
2) structure: largest component, hollow cylinders
3) function: provide support for the cell, to aid in cell division, and to provide a route for intracellular transport.
88
pseudopods
used to capture prey
89
cilia and flagella
move whole cells or material across the cell sruface
90
functional categories of organelles
1) manufactoring - nucleus, ribosomes, ER, golgi
2) breakdown/storage - lysosomes, peroxisomes, vacuoles
3) energy processing - chloroplasts, mitochondria
4) support, movement, and communication - cytoskeleton, cell walls, extracellular matrix, cell junctions
91
function of plasma membrane
forms a boundary between a living cell and its surroundings, exhibits selective permeability, controls traffic of molecules in and out
92
attachment proteins
attach to the extracellular matrix and cytoskeleton, help support the membrane, can coordinate external and internal changes
93
junction proteins
form intercellular junctions that attach adjacent cells
94
glycoproteins
serve as ID tags, may be recognized by membrane proteins of other cells
95
transport proteins
allow specific ions or molecules to enter or exit the cell
96
enzymes
some membranes proteins are enzymes, enzymes may be grouped to carry out sequential reactions
97
receptor proteins
signaling molecules to bind to receptor proteins, receptor proteins relay the message by activating other molecules inside the cell
98
diffusion
the tendency for particles to spread out evenly in an available space down a concentration gradient, area of high concentration to low concentration
99
non polar gases...
diffuse through membrane
100
passive transport
no energy is used to diffuse them, down concentration
101
active transport
up concentration gradient, energy is required (ATP)
102
facilitated transport
requires a protein is it can no pass through regularly
103
factors affecting diffusion rate
1) steepness of concentration gradient. - steeper gradient, faster diffusion
2) molecular size. - smaller molecules, faster diffusion
3) temperature. - higher temperature, faster diffusion.
4) electrical or pressure gradient - charge ions
104
osmosis
diffusion of water across a membrane
105
osmoregulation
water balance
106
tonicity
tendency to gain or lose water
107
isotonic solution
solute concentration is the same as in the cell, animal cells remain constant, plant cells becomes flaccid - not enough water
108
hypotonic
solute concentration is lower than the cell, animal cell lyses and eventually explodes, plant cell becomes turgid - plants like
109
hypertonic
solute concentration is higher, animal cells shrivel collapses, plant cells shrivel up - plasmolyze.
110
endocytosis
membranes may fold inward forming, a vesicle, enclosing material from the outside, in membrane folds
111
exocytosis
a vesicle may fuse with the membrane and expel its contents outside the cell
112
which one, endocytosis or exocytosis, requires energy
both
113
three ways endocytosis can occur
1) phagocytosis ("cell eating") - eats whole cell
2) pinocytosis ("cell drinking") - engulfs solutions
3) receptor-mediated enocytosis
114
bulk transport
moving large molecules, or a whole group of molecules. even whole cells
115
what is energy
the capacity to work, life depends on the fact that energy can be converted from one form to another
116
kinetic energy
energy of motion (including heat and light)
117
potential energy
stored (chemical and positional)
118
one way flow of energy
1) producers capture some of the suns energy
2) cells release the energy in the sugars and capture some of the energy in the chemical bonds
3) cells release the energy and use some of it to do work in the cell
*energy becomes less and less concentrated in this process
119
second law of thermodynamics
energy transformations increase disorder, or entropy while come energy is lost at heat
120
exergonic reactions
releases energy, ex. burning and cellular respiration
121
endergonic reactions
requires an input of energy from the surroundings, ex. phtotsynthesis, biosynthesis
122
ATP...
holds chemical energy and drives cellular work
123
endergonic (ATP)
ADP +energy ----> ATP (carrier of energy)
124
exergonic (ATP)
ATP -----> ADP + energy
125
activation energy
amount of energy that must be input before an exergonic reaction will proceed
126
enzymes are....
proteins that function as biological catalysts
- increases the rate of a reaction without themselves being changed
- decrease the activation energy needed to begin a reaction
127
substrate
a specific reactant that an enzyme acts on
128
active site
a pocket on the enzymes surface that the substrate fits into
129
induced fit
the way the active site changes shape to "embrace" the substrate
130
organismic respiration
breathing
131
cellular respiration
breakdown of sugar
132
slow-twitch fibers undergo....
aerobic respiration, in the presence of O2, also called cellular respiration, ex - marathon runners
133
fast-twitch fibers undergo.....
anaerobic respiration, in the absence of O2, also called fermentation, ex - sprinters
134
anaerobic pathways
1)evolved first
2) doesn't require oxygen
3) start with glycolysis in cytoplasm
4) completed in cytoplasm
5) small amount of ATP generated
135
aerobic pathways
1) evolved later
2) require oxygen
3) start with glycolysis in cytoplasm
4) completed in mitochondria
5) lots of ATP generated
136
substrate - level phosphorylation
substrate gives energy and phosphate group to ADP and makes small amount of ATP
137
oxidative phosphorylation
the energy available to a cell is contained in the arrangement of electrons in chemical bonds, each step involve redox reactions
138
oxidation
loss of electrons(or hydrogen atoms)
139
reduction
addition of electrons (or hydrogen atoms)
140
dehydrogenase
enzymes transferring electrons from H-atoms to other molecules
141
cellular respiration
1)glycolysis
2)citric acid cylcss or krebs cycle
3) electron transport chain
142
glycolysis
Glucose (6 C) ------> pyruvate (3 C)
happens in the cytoplasm
net ATP = 2
also produces NADH
143
intermediate step
Pyruvate (3 C) + CoA -----> Acetyl CoA (2 C)
happens in the mitochondrial matrix
no ATP
produces CO2 and NADH
144
Krebs cycle
Acetyl CoA (2 C) + Oxaloacetate (4 C) --------> Citrate (6 C)
happens in the mitochondrial matrix
net ATP = 2
produces NADH, FADH2, CO2
145
Electron transport chain
1. electron from NADH and FADH2 transferred along chain
2. H+ pumped across membrane to make H+ gradient
3. H+ flow through ATP synthase
happens in inner mitochondrial membrane
net ATP = 28
produces H2O
146
fermentation
begins with glycolysis, yields 2 ATP from glycolysis, steps after glycolysis serve only to recycle NADH
147
lactic acid fermentation (muscles)
NADH is oxidized to NAD+ ad pyruvate is reduced to lactate
148
alcohol fermentation
brewing and baking, yeast and bacteria
149
strict anaerobes
require anaerobic conditions to generate ATP by fermentation, poisoned by oxygen
