Chapter 3 PPT Flashcards
1
Q
The cell is
A
the basic unit of structure and function in the body
2
Q
cells are measured in
A
micrometers
3
Q
cells that have developed specialized characteristics are said to be
A
differentiated
4
Q
What are the three major parts of a cell?
A
Nucleus
Cytoplasm
Cell Membrane
5
Q
Cytoplasm consists of
A
organelles, with specific functions, suspended in a liquid called cytosol
6
Q
What does the cell membrane do?
A
It is the outer boundary of the cell and maintains integrity of the cell.
7
Q
Cell Membrane regulates
A
entry and exit of substances, meaning it is selectively permeable.
8
Q
What is signal transfuction?
A
Permits cells to receive and respond to messages
9
Q
What does the cell membrane consist of?
A
Mainly of lipids and proteins, with some carbohydrates
10
Q
Cell membrane framework is a
A
phospholipid bilayer
11
Q
What forms the surface of the phosopholipid bilayer?
A
Water-soluble (hydrophilic) heads
12
Q
What forms the interior of the phosopholipid bilayer?
A
Water-insoluble (hydrophobic) tails
13
Q
Bilayer is permeable to
A
lipid-soluble substances
14
Q
bilayer is impermeable to
A
water-soluble substances
15
Q
What does Cholesterol do with the cell membrane?
A
Stabilizes membrane, and helps keep it impermeable to water-soluble susbtances
16
Q
What do Carbohydrates do with the cell membrane?
A
Cel recognition and interaction, cell markers
17
Q
What do Mutations in Na+ Channels cause?
A
Inability to feel pain or extreme pain conditions
18
Q
What do mutations in K+ channels cause?
A
Can disrupt electrical activity of the heart and disturb heart rhythm, and/or impair hearing
19
Q
What do abnormal Cl- channels cause?
A
Cystic Fibrosis: Production of thick mucus which causes difficulty breathing, clogged pancreas, salty sweat
20
Q
What do CAMs do?
A
Guide cells on the move
21
Q
What do Selectins do?
A
Coat white blood cells and anchor them by providing friction
22
Q
What do Integrins do?
A
Direct white blood cells through capillary walls toward infection sites .Integrins guide embryonic cells toward maternal cells to form placenta and establish connectiosn between nerve cells
23
Q
What does cytoplasm consist of?
A
Networks of membranes and organelles suspended in cytosol.
24
Q
What is cytosol?
A
Fluid portion of the cytoplasm
25
What are organelles?
Tiny soldi structures with specific functions in the cells
26
What are ribosomes?
Composed of protein and RNA. Free in cytoplasm or on RER
Provides structural support and enzyme activity to link amino acids in protein synthesis
27
What is the Endoplasmic Reticulum
Membrane-Bound Sacs, Canals, Vesicles
Tubular Transport System
28
ER- Rough ER contains
ribosomes, conducts protein synthesis
29
ER- Smooth ER
does not have ribosomes, conducts lipid synthesis
30
What are vesicles?
membranous sacs
| Store or transport substances
31
What is the Golgi apparatus?
Sacs of flattened membranous sacs
Refines, packages, and delivers proteins made on the RER
32
Structure of Mitochondria?
Membrane-bound, fluid-filled sacs
33
Mitochondria houses
chemical reactions that extract energy from nutrients (cellular respiration, which produces ATP)
34
Lysosomes Structure
Small membranous sacs
35
Lysosomes description?
Contains enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, debris, worn out cell parts
36
Lysosomes also known as
"garbage disposals" of cell
37
Peroxisomes structure?
Membranous sacs similar to lysosomes
38
Peroxisomes Descrption?
Contain enzymes that digest lipids, alcohol, hydrogen peroxide
39
What are microfilaments, microtubulues, and intermediate filaments?
Thread-like structures in cytoplasm. Create the cytoskeleton
40
What are microfilaments?
Tiny rods of actin; provide cellular movement such as muscle contractions.
Larger tubes of tubulin, rigidity maintains cell shape, make up cilia, flagella, and centrioles. And helps move organelles.
41
What are intermediate filaments?
Composed of several proteins. A cytoskeletal structure. Supports nuclear envelope
42
What is a centrosome?
"Central Body" consisting of two centrioles
43
Where is the centrosome located at?
in cytoplasm, near nucleus
44
Centrosome structure?
Cylindrical, composed of microtubulues
45
Centrosome Function?
Produce spindle fibers during cell division, which distribute chromosomes to forming daughter cells
46
Cilia are
motile extensions of cell membrane
47
cilia consist of
microtubulues in cylindrical pattern
48
cilia form
a "fringe" on surface of certain epithelial cells
49
cilia are shorter
than flagella, but very abundant when present
50
cilia propel
mucus in respiratory tract, propel egg toward uterus
51
flagella are another type of
motile extension from cell membrane
52
flagella are
similar in structure to cilia, but much longer
53
flagellum causes
the entire cell to move
54
tail of a sperm cell is
the only flagellum in a human cell
55
What is Melas?
Mutant gene in DNA of mitochondria
56
How does Melas affect a person?
Person cannot extract maximum energy from nutritents
57
What is Krabbe Disease?
Caused by inability to produce one lysosomal enzyme
58
How does Krabbes Disease affect a person?
Person cannot produce myelin for nerve cells, which leads to severe damage to the nervous system
59
What is ADL?
Caused by lack of a protein in membrane of peroxisomes
60
How does ADL affect a person?
Fatty acid buildup destroys myelin sheath of nerve cells. Nerve cells cannot transmit nerve impulses fast enough
61
What is the nuclear envelope?
Porous double layered membrane that separates nucleoplasm from cytoplasm. Nuclear pores allows passage of certain substances
62
What is a nucleolus?
Dense body of RNa and Protein. Site of ribosome production
63
What is a chromatin?
COnsists of cell's chromsomes, each containing DNA wound around proteins. Stores information for protein synthesis
64
What are the Passive Processes?
Diffusion, Osmosis, Facilitated Diffusion , and Filtration
65
What are the Active Processes?
Active Transport
Endocytosis
Exocytosis
Transcytosis
66
What is Diffusionn?
Movement of atoms, molecules, or ions from region of higher concentration to region or lower concentration
67
Diffusion occurs
due to constant motion of atoms, molecules, and ions
68
Diffusion, only substances
that the cell membrane is permeable to. Oxygen, CO2, and other lipid soluble substances
69
What kind of process is diffusion?
Passive, no ATP required
70
Example of Diffusion?
A dissolving sugar cube
71
What is Facilitated Diffusion?
Diffusion across the cell membrane through ion channels or transporters
72
Facilitated Diffusion contains what water-soluble substances?
Na+, K+, Cl-, Glucose, Amino Acids
73
What kind of process is Facilitated Diffusion?
PAssive Process, no ATP required
74
What is Osmosis?
movement of water across a selectively permeable membrane from a region of higher water concentration to a region of lower water concentration
75
osmosis- water moves into
a region containing higher impermeant solute concentration
76
what kind of process is osmosis?
Passive process, no ATP required
77
what is osmotic pressure?
ability of osmosis to generate enough pressure to lift a volume of water.
78
Osmotic pressures inceases as
the concentration of impermeant solute increases
79
What is a isotonic solution?
Same osmotic pressure. Cells in an isotonic solution have no neet gain or loss of water
80
what is a hypertonic solution?
higher osmotic pressure.
cells in a hypertonic solution lose water
81
what is a hypotonic solution?
lower osmotic pressure
cells in a hypotonic solution gain water
82
What is filtration?
process that forces molecules through membranes by exerting pressure
83
What is filtration used for?
used to separate solids from water, or small particles from large ones
84
example of filtration?
when blood plasma leaves capillaries, water and small solutes are filtered, but large plasma proteins are not
85
what type of process is filtration?
passive process, requires no ATP
86
what is active transport?
movement of substances across a membrane from region of lower concentration to region of higher concentration against a concentration gradient
87
active transport uses
carrier molecules in cell membrane
88
what kind of process is active transport
active process, requires ATP
89
examples of active transport?
sugars, amino acids, Ca+ H+ Na/K Pump
90
what is endocytosis?
movement of a substance into the cell inside a vesicle
91
Three types of endocytosis?
Pinocytosis
Phagocytosis
Receptor-Mediated Endocytosis
92
what is pinocytosis?
membrane engulfs droplets of liquid
93
what is phagocytosis?
membrane engulfs solid particles
94
what is receptor-mediated endocytosis?
membrane engulfs specific substances, which have bound to receptor proteins on the membrane
95
what is exocytosis?
release of substances/particles from cell
96
Exocytosis - vesicles containing particles..
fuse with cell membrane and release contents
97
example of exocytosis?
release of neurotransmitter from nerve cells
98
what does transcytosis involve?
involves receptor-mediated endocytosis followed by exocytosis
99
transcytosis quickly..
transports substances from one end of cell to the other
100
transcytosis moves
substances across barriers form by tightly connected cells
101
example of transcytosis?
transport of hiv across lining of anus or vagina
102
What is a cell cycle?
series of changes a cell undergoes from the time it forms until the time it divides
103
stages of cell cycle?
Inteprhase
Mitosis
Cytokinesis
104
Interphase is a
very active period in cell cycle where cell grows and maintains normal functions
105
Interphase - cell
replicates DNA to prepare for mitosis
106
Interphase - cell synthesizes
organelles, membranes, and biochemicals to prepare for cytokinesis
107
Phases of Interphase?
S Phase
G1 and G2 Phases
108
What is S Phase?
DNa is replicated during this
109
What is G1 and G2 Phase?
Structures other thana DNa are replicated and cell grows during this.
110
Mitosis produces
two daughter cells from an original somatic cell
111
what is mitosis?
division of the nucleus
112
what is cytokinesis?
division of the cytoplasm
113
Phases of Mitosis?
Prophase
Metaphase
Anaphase
Telophase
114
What is Prophase
Chromatin condenses to form chromosomes, centrioles move to opposite sides of cytoplasm, nuclear envelope and nucleolus disperse
115
what is metaphase
spindle fibers from centrioles attach to chromsomes and align them midway between centrioles
116
what is anaphase?
chromosomes separate and move in opposite directions toward centrioles as the spindle fibers shorten
117
what is telophase?
chromosomes return to chromatin structure, nuclear envelope forms around each chromosome set, and nucleoli became visible
118
What is cytokinesis?
cytoplasmic division
119
when does cytokinesis begin?
during anaphase
120
cytokinesis continues through
telophase
121
what happens during cytokinesis?
contractile ring of actin filaments pinches cytoplasm in half.
122
after cytokinesis, newly formed cells will
have identical DNA, may have slightly different size and number of organelles
123
SKin cells, intestinal cells, and blood -forming cells with divide
often and continually
124
neurons divide
a specific number of times, and then cease
125
chromosome tipis (telomeres) that shorten with each mitosis provide
a miotic clock
126
What is contact inhibition?
healthy cells stop dividing when they become crowded. Tumors can result from a loss of control over the frequency of mitosis
127
what are 2 types of tumors?
benign and malignant
128
what is a benign tumor?
remains in local area
129
what is a malignant tumor?
invasive, cancerous, can spread or metastasize
130
two major types of genes that cause cancer?
oncogenes
tumor suppressor genes
131
what are oncogenes?
abnormal forms of genes that control cell cycle but are overexpressed
132
what are tumor suppressor genes?
normally limit mitosis, but if inactivated/removed, cannot regulate mitosis
133
what is differentiaition?
process of specialization of cells
134
stem cells can divide to
form two new stem cells, called self-renewal
135
stem cells can also divide to
form a stem cell and a progenitor cell
136
stem cells can differentiate as
any of many cell types
137
what is a progenitor cell?
partially specialized stem cell, daughter of stem cell
138
progenitor cell can divide to
become any of a restricted number of cells, called a "committed cell"
139
what is totipotent?
daughter cells that can specialize to become any cell type?
140
totoipotent examples?
fertilized egg, cells of early embryo
141
what is pluripotent?
daughter cells that can become a limit number of cell types
142
examples of pluripotent?
stem cells of later development, progenitor cells
143
Example of differentiation
a fertilized egg has the ability to produce any type of human cell, while partially differentiate dcells can only produce some types or a sngle type of cell
144
stem and progenitor cells are required for
growth and healing
145
what is regenerative medicine?
field that uses bodys ability to generate new cells to treat diseases and injuries; includes stem cell technology
146
sources of stem cells for research, treating diease/injuries
donor stem cells
stem cells from patients
147
where do donor stem cells come from?
such as umbilical cord cells
148
where do stem cells from patients come from?
either form natural site, such as bone marrow, or reprogrammed differentiated cells grown in cell culture
149
what is apoptosis?
programmed cell death that is a normal part of development
150
apoptosis removes
webbing between fetal fingers and toes
151
apoptosis- protective
pells away damaged skin after a sunburn
152
what is necrosis
cell death from damage, not a normal process
