Unit 3 Flashcards
(121 cards)
1
Q
An outer covering that separates the cell’s interior from its surrounding enviroment
A
Plasma membrane
2
Q
Consisting of a jelly-like cytosol within the cell in which other cellular components are found
A
Cytoplasm
3
Q
The genetic material of the cell
A
DNA
4
Q
A usable copy of the genetics instructions
A
RNA
5
Q
Synthesizes proteins
A
Ribosomes
6
Q
Is a simple, mostly single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle
A
Prokayote
7
Q
Prokaryotic DNA is found in a central part of the cell called the
A
Nucleoid
8
Q
Dynamic structure allowing lateral movement of components
A
Fluid mosaic model
9
Q
What is the membrane structure composed of?
A
Composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates
10
Q
Three types of transport mechanisms
A
Passive transport
Active transport
Bulk Transport
11
Q
Three types of passive transport
A
Diffusion
Osmosis
Facilitated diffusion
12
Q
Two types of bulk transport
A
Endocytosis
Exocytosis
13
Q
Type of passive transport: Movement of small, nonpolar molecules (e.x. O2, CO2) down their concentration gradient
A
Diffusion
14
Q
Type of passive transport: Water movement through aquaporins
A
Osmosis
15
Q
Type of passive transport: Channel/carrier proteins assist polar/charged molecules (e.x. glucose)
A
Facilitated diffusion
16
Q
is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes
A
Osmosis
17
Q
Is the random movement of molecules toward state of equilibrium
A
Diffusion
18
Q
Occurs when particles continue to move, but there is no net change in distribution
A
Equilibrium
19
Q
Factors affecting diffusion
A
Diameter
Temperature
Electric charges
Concentration
Rate
20
Q
Biological membranes are ____________; they allow some substances to pass through while others can not
A
Selectively permeable
21
Q
The cell has a higher concentration of solute then outside the cell, so water moves into the cell
A
Outside cell is hypotonic
Inside cell is hypertonic
Cell will swell
22
Q
The cell has a lower concentration of solute than outside the cell, so water leaves the cell
A
Outside cell is hypertonic
Inside cell is hypotonic
Cell will shrink
23
Q
Samer concentration of solute in and out of the cell
Water is flowing in and out at the same rate
A
Isotonic
No change in cell volume
24
Q
Prevents cell from bursting by creating a physical barrier
A
Cell wall
25
Are organelles that actively pump water out of the cell
Contractile vacuoles
ex) protists
26
Cell membranes are bilayered, dynamic structures that:
Perform vital physiological roles
-Form boundaries between cells and their environment
-Regulate movement of molecules between compartments (phospholipid bilayer)
27
How does the temperature affect the membranes fluidity
Increases ---> Fluidity increases
Decreases ----> Fluidity decreases
28
How does fatty acid saturation affect the membranes fluidity
Increase saturation ---> Decrease fluidity
Decrease saturation ---> increases fluidity
29
How does cholesterol content affect the membranes fluidity
Increases fluidity, but at a certain point of adding cholesterol it starts to decrease fluidity
30
All biological membranes contain __________
-What are the three types of them
Proteins
-Integral membrane proteins
-Transmembrane proteins
-Peripheral membrane proteins
31
Any protein that is in the membrane
Integral membrane proteins
32
Any integral membrane protein that passes through the entire membrane
Transmembrane protein
33
Proteins located by the membrane but are not tied/attached to the membrane
Peripheral membrane proteins
34
Membranes can...
Process information
-Harness energy
-Organize interactions
-Mediate interactions
-Facilitate transport
35
Are integral transmembrane proteins which contain a pore via which molecules may cross from one side of the membrane to the other
Channel proteins
36
Channel proteins are ___________ and may be ________ to regulate the passage of ions in response to certain stimuli
Ion-selective
Gated
37
Channel proteins only move molecules along a _______________
-Channel proteins are not used in ______________
-Channels are ___________
Concentration gradient
Active transport
Bidirectional
38
The diffusion of molecules across membranes via a protein molecule is called _____________
-It is a passive process and does not require an expenditure of energy
Facilitated diffusion
39
____________ requires direct hydrolysis of ATP
Primary active transport
40
In _____________ the energy for transport comes from an ion concentration gradient that is established by primary active transport
Secondary active transport
41
An important membrane adaption for active transport is the presence of specific carrier proteins or pumps to facilitate movement: there are three types of these proteins or transporters
Uniporter
Symporter
Antiporter
42
a _______ carries one specific ion or molecules (type of carrier proteins)
Uniporter
43
A _________ carries two different ions or molecules, both in the same direction (type of carrier protein)
Symporter
44
A _________ also carries two different ions or molecules, but in different directions (Type of carrier protein)
Antiporter
45
Is the process by which a cell brings macromolecules, large particles, small molecules, and even other cells into eukaryotic cells in vesicles
Endocytosis
46
Moves materials packaged in vesicles to the membrane for secretion
Exocytosis
47
Involves the largest vesicles/vacuoles
-Entire cells can be engulfed
-Common among unicellular protists
-White blood cells use this to defend body against invading foreign cells
Phagocytosis
48
Involves formation of small vesicles dissolved substances and fluids are brought into cell
-In mammals, a single layer of cells separating capillaries from surrounding tissue uses this to acquire fluids from blood
Pinocytosis
49
Specific interactions between cell surface proteins (receptors) and secreted proteins (ligands) can trigger the formation of membrane coated pits
Receptor-mediated endocytosis
50
A protein that receives a signal and initiates a cellular response
Receptor
51
A molecule that interacts with a receptor to trigger a cellular response
Ligand
52
Types of signaling
Paracrine
Autocrine
Juxtracrine
Endocrine
53
Signals that act locally between cells that are close together are called __________
Paracrine signals
54
Signals from distant cells are called ______________, and they originate from endocrine cells
Endocrine signals
55
______________ are produced by signaling cells that can also bind to the ligand that is released
-This means the signaling cell and the target cell can be the same or a similar cell
-This type of signaling often occurs during the early development of an organism to ensure that cells develop into the correct tissues and take on the proper function
Autocrine signals
56
Gap junctions in animals and plasmodesmata in plants are connections between the plasma membranes of neighboring cells. These water-filled channels allow small signaling molecules, called _____________, to diffuse between the two cells
Intracellular mediators
57
Hydrophobic (steroid) signaling molecules are nonpolar lipids and can cross through the membrane unassisted. Their receptors are located in the ____________
Cytosol
58
Many chemical signals and most proteins are hydrophilic. They can not pass through the membrane, so their receptors are ______________
Transmembrane proteins
59
Physical interaction:
-Molecular activity can be altered by the absence or presence of noncovalent ___________
Binding partners
60
Chemical modification:
-Molecular activity can be altered by the addition or removal of covalent ____________
Functional groups
ex) phosphate, amino acids, and methyl
61
Three types of receptors
Gated ion channel receptors
Enzyme-linked receptors
G-protein coupled receptors
62
____________ are free floating in the cytoplasm. They are often called nuclear receptors
Cytosolic receptors
63
______________ transduce signals by directly catalyzing a reaction inside the cell
Enzyme-linked receptors
64
Upon interaction with their ligand, enzyme-linked receptors become catalytically active. Many are ____________, and transfer phosphates from ATP to other proteins (substrates). Phosphorylated substrates in turn can interact with and trigger other pathway molecules
Kinase
65
Integral transmembrane protein, passes through the membrane seven times
-Also called a serpentine receptor
G protein linked receptor (GPCR)
66
Three-protein complex
-Attached to the membrane through a lipid anchor
-Binds guanine nucleotides
Trimeric G protein
67
Active G-proteins interact with and trigger membrane-bound enzymatic ______________ (partner molecules). Once activated, these enzymes catalyze the production of _____________. A single signal molecule can stimulate the production of many second messenger molecules, amplifying the original signal
Effector molecules
Second messengers
68
____________ are small diffusible molecules that transduce signals indirectly
-They have no catalytic activity
-They are not targeted- they move about freely by diffusion
-They aren't restricted to a single role or cell type
Second messengers
69
__________lack a nucleus or other membrane-enclosed compartments and lack distinct organelles
Prokaryotes
70
______________ have a membrane-enclosed nucleus and other membrane-enclosed compartments or organelles as well
Eukaryotes
71
Eukaryotic cells are larger and more complex than prokaryotic cells. _____________ is key to eukaryotic cell function
Compartmentalization
72
The ______________ is the entire region of a cell between the plasma membrane and the nuclear envelope. It is made up of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals
Cytoplasm
73
The ____________ houses the cell-s DNA and directs the synthesis of ribosomes and proteins
Nucleus
74
_______________ is a double-membrane structure that constitutes the outermost portion of the nucleus. Both the inner and outer membranes of this are phospholipid bilayers
Nucleoplasm
75
__________ are the cellular structures for protein synthesis
Ribosomes
76
_____________ are often called the "powerhouse" or "energy factories" of a cell because they are responsible for making adenosine triphosphate (ATP), the cell's main energy-carrying molecule
Mitochondria
77
Enzymes within this aid the breakdown of proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles
-Only found in animal cells
-Called the "garbage disposal"
Lysosomes
78
__________ are plant cells organelles that carry out photosynthesis
Chloroplasts
79
The ___________ is a series of interconnected membranous sacs and tubules that collectively modifies proteins and synthesizes lipids
Endoplasmic reticulum (ER)
80
The ____________ has ribosomes attached to its cytoplasmic surface
-Ribosomes transfer their newly synthesized proteins into the lumen of this where they undergo structural modifications, such as folding or the acquisition of side chains. These modified proteins will be incorporated into cellular membranes or secreted from the cell (such as protein hormones, enzymes). This also makes phospholipids for cellular membranes
Rough endoplasmic reticulum (RER)
81
The __________ has few to no ribosomes on its cytoplasmic surface
-Functions of this include synthesis of carbohydrates, lipids, and steroid hormones; detoxification of medications and poisons; and storage of calcium ions
Smooth endoplasmic reticulum (SER)
82
Sorting, tagging, packaging, and distribution of lipids and proteins takes place in the ___________, a series of flattened membranes
Golgi apparatus
83
Maintains cell shape and support and positions organelles
-Provides mechanisms for cell movement
-Acts as tracks for "motor proteins" that help move materials within cells
Cytoskeleton
84
Three types of cytoskeleton
Microfilaments
Intermediate filaments
Microtubules
85
Made of fibrous protein monomers, intertwined into larger, thicker cords
-Flexible, rope-like assemblages
-Stabilize cell structure
-Resist tension
-Not very dynamic; once they are together, they will normally just stay together
Intermediate filaments
86
Made of protein monomer actin
-Exist as single filaments, in bundles, or in networks
-Needed for cell contraction
-Involved in cytoplasmic streaming and formation of pseudopodia, "cell crawling"
Microfilaments
87
___________ are microfilament motor proteins. Interactions between the tail region of separate myosin dimers create multi-headed moto cables capable of immense contractile strength
Myosin
88
Hollow cylinders made of tubulin protein-dimer subunits
-Provide rigid intracellular skeleton for some cells
-Function as tracks that motor proteins can move along in cell
-Regularly form and disassemble as needs change
Microtubules
89
____________ are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell
ex) sperm
Flagella
90
_________ are present many of them extend along the entire surface of the plasma membrane. They are short, hair-like structures that are used to move entire cells or substances along the outer surface of the cell
Cilia
91
___________ organisms can link inorganic carbon molecules (CO2) to make larger organic molecules cells need. They can literally make their own food
Autotrophic
92
_______________ organisms can only process organic molecules, they can not start with inorganic carbon. They must consume their organic food from other cellular sources
Heterotrophic
93
______________ reaction transfer electrons from one molecule to another. The transfer of electrons is often accompanied by the transfer of hydrogen
Reduction oxidation (Redox)
94
In a Redox reaction the molecule that losses electrons is called
Reducing agent ---> oxidized
95
In a Redox reaction the molecule that gains electrons is called
Oxidizing agent ---> Reduced
96
__________________ exists in reduced (___________) and oxidized (_________) forms. It can serve as an electron shuttle, moving electrons from one redox reaction to another
Nicotinamide adenine dinucleotide
NADH
NAD+
97
_____________ describes the chemical reactions that break, fuse, and/or move atoms between molecules, and the energy requirement of these movements
Metabolism
98
The sugar __________ is the most common source of energy
Glucose (C6H12O6)
99
Where does glycolysis takes place
In the cytosol
100
_________ describes the 10 cytosolic steps used to convert one molecule of glucose into 2 molecules of pyruvate
Glycolysis
101
Glycolysis is divided into two stages
Energy investing: reactions that use ATP
Energy-harvesting: reactions that produce ATP
102
The release of one or two phosphate groups from ATP, a process called ___________, releases energy
Dephosphorylation
103
_____________ refers to the addition of phosphate groups
Phosphorylation
104
______________, a process of ATP production in cellular metabolism, is used to generate 90% of the ATP made during glucose catabolism and is also the method used in the light reactions in photosynthesis to harness the energy of sunlight
Chemiosmosis
105
The production of ATP using the process of chemiosmosis is called __________ because of the involvement of oxygen in the process
Oxidative phosphorylation
106
Is glycolysis aerobic or anaerobic
Anaerobic
107
Products of glycolysis
2 pyruvate molecules
4 ATP molecules (NET gain of 2)
2 molecules of NADH
108
____________ is a 2 carbon and can be processed anabolically to build other molecules in the cell and starts the Citric Acid Cycle
Acetyl-CoA
109
Products of one glucose molecule for glycolysis
2 pyruvate (3C)
2 NADH
2 ATP
110
Products of one glucose for pyruvate oxidation
2 acetyl CoA (2C)
2 NADH
2CO2
111
Products of one glucose for Citric Acid Cycle
4 CO2
6 NADH
2 FADH
2 ATP
112
___________ describes the process by which electron carriers are oxidized in presence of )2 to produce 2 ATP
Oxidative phosphorylation
113
2 stages of oxidative phosphorylation
Electron transport chain
Chemiosmosis
114
Shuttling of electrons provide energy for active transport of H+ ions (protons) across inner mitochondrial membrane
Electron transport chain
115
Potential energy of H+ concentration gradient is used to produce ATP
Chemiosmosis
116
_____________ consist of four large integral membrane protein complexes (I, II, III, IV) bound to ___________ plus ____________ and ___________
Electron transport chain
Inner mitochondrial membrane
Cytochrome (c)
Ubiquinone (q)
117
_____________ is a form of anaerobic metabolism that is capable of recognizing/reoxidizing electron carriers
Fermentation
118
Where does lactic acid fermentation occur
Some microorganisms and in muscle cells
119
How does lactic acid fermentation work
Enzyme converts pyruvate (3C) into lactic acid (2C)
-Pyruvate is the electron acceptor, allowing NAD+ to be replenished
120
How does alcoholic fermentation work
Pyruvate (3C) ---> acetaldehyde (2C) + CO2
-Acetaldehyde reduced by NADH + H+ ---> ethanol + NAD+
121
Where does alcoholic fermentation occur
In yeast and some bacteria and plants
