Exam 2 Flashcards
1
Q
Parts of the cell
A
Plasma membrane, cytoplasm (cytosol and organelles), and nucleus
2
Q
Characteristics of plasma membrane
A
- Composed of phospholipid bilayer 2. Flexible 3. Selective permeability
3
Q
2 arrangement of membrane proteins
A
Integral proteins (including transmembrane proteins) and peripheral proteins
4
Q
Functions of membrane proteins
A
Ion channels, transporters (carriers), receptors (binds to ligands), linkers, and cell identity markers (MHC proteins)
5
Q
True/False: Phospholipids are in constant motion
A
True
6
Q
True/False: Plasma membrane has selective permeable.
A
True
7
Q
What alters permeability?
A
Ion channels and transporters
8
Q
What is permeable to plasma membrane?
A
Small, uncharged, nonpolar molecules (ex: oxygen, CO2)
9
Q
What is weakly permeable to the plasma membranes.
A
Small, uncharged, polar molecules (ex: water)
10
Q
What is impermeable to the plasma membranes?
A
Ions and large molecules
11
Q
Gradients across the membrane is dependent on __________.
A
Selective permeability
12
Q
Two types of gradients across the membrane
A
Concentration and electrical gradient
13
Q
Two types of transport across the membrane
A
Passive and active transport
14
Q
What are the mechanisms of passive transport?
A
Simple diffusion, facilitating diffusion, and osmosis
15
Q
What are the mechanisms of active transport?
A
Transport via transport proteins and transport via vesicles
16
Q
Two forms of active transport
A
Primary and secondary active transport
17
Q
Transport via vesicles
A
Large molecules or large amount of a substance can move across membrane,”packaged” within the vesicle
18
Q
Endocytosis includes:
A
Receptor-mediated endocytosis, phagocytosis, and pinocytosis (bulk-phase endocytosis)
19
Q
Kinds of cytoskeleton
A
Microfilaments, intermediate filaments and microtubules
20
Q
What does reticulum mean?
A
Network
21
Q
Two types of ER
A
Rough and smooth ER
22
Q
What is the function of vesicles that pinch off from mature cisternae at other end of Golgi complex?
A
Either store proteins (lysosomes) or deliver proteins to plasma membrane for insertion in membrane for insertion in membrane or exocytosis
23
Q
How many chromosomes does a human somatic (body cell) have?
A
46
24
Q
Two stages of gene expression
A
Transcription and translation
25
Where does transcription occur?
In the nucleus
26
3 types of RNA
mRNA, rRNA, tRNA
27
Where does the RNA polymerase attaches to start transcription?
A DNA molecule at a promoter sequence
28
Where does the process of transcription ends?
At terminator sequence in DNA
29
Where does translation occurs?
In cytoplasm, often on rough ER
30
Describe the ribosomal structure.
1. Small subunit has binding site for mRNA 2. Large subunit has two binding sites for tRNA
31
Two binding sites in the large subunit for tRNA
P site and A site
32
What is always the first amino acid in translation?
Met
33
What is the process for somatic (soma= body) cell division?
Mitosis; one diploid parent (2N) parent cell --\> two 2N daughter cells
34
What is the process for reproductive cell division?
Meiosis; one 2N parent cell --\> 4 haploid (1N) cells (gametes)
35
2 phases of somatic cell cycle
Interphase and mitotic phase
36
3 phases of interphase
G1, S, and G2 phases
37
Mitotic phase includes?
Mitosis and cytokinesis
38
4 stages of mitosis
Prophase, metaphase, anaphase, and telophase
39
Tissue structure and function depend on:
Cell types Types of connections between cells Nature of extracellular materials
40
Four types of tissues in human body
Epithelial Connective Muscular Nervous
41
Five types of cell junctions
Tight and adherens junction desmosome hemidesmosome gap junction
42
Basic structural and functional unit of living organisms
Cell
43
Allows for movement of membrane during growth, maintenance, and repair; plasma membrane and its components can move
Membrane fluidity
44
Requires no energy input from the cell; a substance moves down its concentration or electrical gradient
Passive transport
45
Requires energy input from cell; a substances drive against its concentration or electrical gradient
Active transport
46
Molecules move from an area of high concentration to area of low concentration until equilibrium is reached; small, uncharged molecules (polar or nonpolar) diffuse across membrane, ex: O2, CO2, H2O
Simple diffusion
47
Large, charged, or highly polar molecules require assistance to move across membrane: uses ion channels and transporters proteins
Facilitated diffusion
48
Diffusion of solvent (WATER) across a selectively permeable membrane; moves from area of higher water conc. to area of lower water conc.; moves from area of lower solute conc. to area of higher solute conc.
Osmosis
49
Pressure driving water from area of low to area of high solute concentration
Osmotic pressure
50
Ability of a solution to change the volume of a cell by osmosis; relative concentration of solution of the ECF and ICF
Toxicity
51
ECF and ICF have same concentration of solutes; no net movement of water and cell does not change volume
Isotonic solution
52
ECF had less solute than ICF; water enters cell faster than it leaves; cells swells and my burst (lyse)
Hypotonic solution
53
ECF has more solutes than ICF; water leaves cell faster than it enters; cell shrinks (crenation)
Hypertonic solution
54
By expending energy, cells can move molecules against their concentration or electrical gradient
Active transport
55
Energy derived from ATP and used to change shape of transporter protein; ex: sodium potassium pump
Primary active transport
56
Energy derived from an ion concentration gradient (usually Na+) and energy is used to change shape of transporter protein; simultaneously moves Na+ and another molecule
Secondary active transport
57
Small sac formed by budding off from an existing membrane
Vesicle
58
Movement of substances into cell via vesicles
Endocytosis
59
Cell takes in select molecules (ligands); molecule binds to receptor protein on plasma membrane; transports to individual molecules and highly specific
Receptor-mediated endocytosis
60
Cell engulfs large solid particles; molecules bind to receptor proteins, transports individual molecules of larger particles and highly specific
Phagocytosis
61
Cell engulfs fluid (and dissolved solute); no receptor proteins are involved and transports many molecules at once (not specific)
Pinocytosis (bulk-phase endocytosis)
62
Movement of substances out of cell via vesicles; vesicle formed inside cell and fuses with plasma membrane to release contents
Exocytosis
63
Movement of substances across a cell via vesicles; linking endocytosis at one cell surface and exocytosis at other surface
Transcytosis
64
Network of protein filaments extending throughout cytosol
Cytoskeleton
65
Small in size; composed of actin and provide structural support for cell; involved in cell movement
Microfilaments
66
Medium size; composed of several different proteins and provide structural support for cell; holds nucleus and other organelles in place
Intermediate filaments
67
Large size; composed of tubulin molecules arranged in hollow tubes; determines shape of cell and involved in movement of organelles, chromosomes, cilia and flagella
Microtubules
68
Composed of microtubules; project from surface of some cells; unreliable and short and involved in movement of extracellular fluid
Cilia
69
Composed of microtubules; project from surface of some cells; singular and long and propels cell from fluid
Flagella
70
Located near nucleus; composed of two centrioles and is the organization cent for mitosis spindle
Centrosome
71
Composed of two protein subunits; contain rRNA; most attached to endoplasmic reticulum and function is protein synthesis
Ribosome
72
Network of membranes extending throughout the cell, forming flattened sacs or tubules
Endoplasmic reticulum (ER)
73
Folded into series of flattened sacs; ribosomes attached to outer surface and proteins synthesize by ribosomes are modified inside sacs formed by ER
Rough ER
74
Lack of ribosomes; site of synthesis of fatty acids and steroids
Smooth ER
75
Transports proteins throughout cell or to cell surface for secretion; Series of flattened membranous sacs (cisternae/cisterna = cavities); Looks like a cup
Golgi complex
76
carry proteins from rough ER to Golgi complex, creating the young cisternae at one end of Golgi complex
Transport vesicles
77
Membrane-bound organelle; "Powerhouse" of the cell; Site of most of ATP production via aerobic respiration
Mitochondria
78
Control center of the cell; A double membrane composed of two phospholipid bilayers; Contains nucleolus/nucleoli; Contains genetic information for cell structure and function
Nucleus
79
Allow substances to cross the nuclear envelope (passive or active transport)
Nuclear pores
80
Sites of ribosome formation
Nucleolus/nucleoli
81
A section of a DNA molecule that codes for a particular protein; composed of a sequence of base triplets
Gene
82
A sequence of three nucleotides; codes for a particular amino acid in the protein
Base triplets
83
DNA uses a template to synthesize a protein
Gene expression
84
Information encoded in DNA copied to mRNA; Base triplets of DNA transcribed as a codon in mRNA
Transcription
85
Information encoded in RNA used by ribosome to produce protein; Codons of mRNA for amino acids in protein
Translation
86
Gametes and precursors
Germ cells
87
Period of metabolic activity and cell growth; Chromosomes and organelles have duplicate Chromosomes in diffuse form (chromatin) Nuclear envelope intact
Interphase
88
Period of cell division
Mitotic phase
89
Metabolic activity Replication of organelles Centrosome replication begins
G1 phase (G = growth)
90
Replication of DNA Double helix partially uncoils Each strand serves as a template for the synthesis of a new complementary strand
S phase (S=synthesis)
91
Metabolic activity Cell growth Centrosome replication is completed
G2 phase
92
Division of nucleus (including chromosomes) between daughter cells; a continuous process
Mitosis
93
Division of cytoplasm (including organelles) between daughter cells
Cytokinesis
94
Nuclear envelope disintegrates Chromosomes in condensed form (chromatid pairs) Homologous chromatids joined by centromere Centrosome begin to produce a mitosis spindle composed of microtubules
Prophase
95
Chromatid pairs line up along equator of the cell Centromeres aligned at the center of the mitotic spindle
Metaphase
96
Centromeres split Members of chromatid pairs (chromosomes)move toward opposite poles of the cell Microtubules of mitotic spindle pull on centromeres of the chromosomes
Anaphase
97
Chromosomes reach opposite poles of the cell New nuclear envelopes form Cytokinesis involves formation of cleavage furrow
Telophase
98
Groups of cells and associated extra cellular materials that work together to perform a particular function
Tissues
99
Cells within a tissue are usually joined together at their plasma membrane
Cell junctions
100
Trans-membrane proteins tightly link cells together; Tissues are relatively impermeable
Tight junction
101
Trans-membrane proteins link cells together; Trans-membrane proteins anchored to microfilaments of cytoskeleton; Tissues resist separation during movement
Adherens junction
102
Trans-membrane proteins link cells together; Trans-membrane proteins anchored to intermediate filaments of cytoskeleton; Tissues resist separation during movement
Desmosome
103
Similar structure to desmosome; Links cells to basement membrane, rather than to other cells
Hemidesmosome
104
Plasma membrane of adjacent cells not touching; Trans-membrane proteins form tubes between cells; Allows for communication between cells
Gap junction
105
Cover body surfaces and line body cavities Form functional regions of glands Cells arranged in continuous sheets
Epithelial tissue
106
Faces body surface or internal body cavity
Apical surface
107
Adheres to basement membrane
Basal surface
108
Consists of basal lamina and reticular lamina
Basement membrane
109
Secreted by overlying epithelial cells
Basal lamina
110
Secreted by underlying connective tissue
Reticular lamina
111
Functions of epithelial tissue
Form selective barriers to passage of susbtances into and out of body
absorption of nutrients
excretion of waste products
secretion of hormones, digestive juices, etc
form protective surfaces against external environment
112
type of epithelial cell that is flattened
squamous epithelium
113
type of epithelial cell that are cubed-shaped or hexagonal
cuboidal epithelium
114
type of epithelial cell that are taller than they are wide
columnar epithelium
115
type of epithelial cell that can change shape as tissue stretches
transitional epithelium
116
type of epithelial cell that is composed of a single cell layer
simple epithelia
117
type of epithelial cell that is composed of multiple cell layers
stratified epithelia
118
type of epithelial cell that is composed of a single cell layer, but individual cells may not extend from basal to apical surface
pesudo-stratified epithelia
119
tissues within a gland that secrete substances
glandular epithelia
120
ductless glands that secrete products (hormones) into interstitial fluid (then blood stream)
endocrine glands
121
glands with ducts that secrete products (mucus, sweat, digestive enzymes, etc.) into ducts that empty to body surface (e.g. sweat gland) or lumen of organ or tract (e.g salivary gland)
exocrine gland
122
3 classifications of exocrine glands
merocrine
apocrine
hoocrine
123
secrete products via secretory vesicles and exocytosis
merocrine glands
124
mammary glands; they secrete products via pinching off of apical surface of cell
apocrine glands
125
sebaceous (oil) glands; secrete products via rupture of cell
holocrine glands
126
connective tissue functions
* binds body structure together
* provides support
* transports nutrients and wastes
* stores energy
* protects body via immune response
127
secreted by fibroblasts
connective tissue fibers
128
type of protein fiber that are thick, straigh, and un-branched; also strong and flexible
collagen fibers
129
type of protein fiber that are thin and branching, strong and flexible
reticular fibers
130
type of protein fiber that are thin and branching, and elastic (returns to original size and shape after stretching)
elasic fibers
131
type of cartilage that found at joints and ends of long bones; reduces friction between articulating bones
hyaline cartilage
132
type of cartilage that frames intervertebral disks and prevents bone-to-bone contact
fibrocartilage
133
type of cartilage found in external ear and provides structural support
elastic cartilage
134
flat sheets of tissue that cover or line part of the body
tissue membranes
135
type of membrane that line body cavities that open to external environment;
forms barrier to pathogens and secretes mucus that prevents dessication
mucous membrane
136
type of membrane that lines internal body cavities and covers organs within internal body cavities
serous membrane
137
type of membrane that consists of epidermis and dermis
cutaneous membrane
138
type of membrane that lines cavities of mvable joints and secretes synovial fluid
synovial membrane
139
layer of the epidermis that has one layer of cuboidal or columnar keratinocytes; contains many stem cells that give rise to new keratinocyes
stratum basale
140
layer of the epidermis that has 8-10 layers of keratinocytes
living cells and keratinocyes begin producing keratin at this stage
stratum spinosum
141
layer of the epidermis with 3-5 layers of flattened keratinocytes, and where the younger keratinocyes produce lamellar granules consisting of hydrophobic keratohyalin that causes dehydration of cell and waterproofs skin
stratum granulosum
142
slayer of the epidermis with 3 to 5 layers of dead, flattened keratinocytes and provides extra protection for thick skin
stratum lucidum
143
layer of the epidermis that has 25-30 layers of dead, flattened keratinocytes; superficial layers are shed and replaced by new layers from below
stratum corneum
144
