Cells Flashcards
(120 cards)
1
Q
What are tissues?
A
Cells that carry out the same general function and are grouped together
2
Q
What are the four basic tissues?
A
Epithelia, connective tissue, muscle, and nerve
3
Q
What is the function of epithelia?
A
To cover and line surfaces (ex. lumen)
4
Q
What is the function of connective tissue?
A
To package, support, and connect
5
Q
What is the function of muscle tissue?
A
Contractility (ex. change size of lumen for smooth muscle)
6
Q
What are the types of muscle tissue?
A
Skeletal, cardiac, and smooth
7
Q
What is the function of nerve tissue?
A
irritability and conduction
8
Q
Definition of Resolution
A
Ability to see two side-by-side dots as separate entities
9
Q
What is the resolution of the unaided human eye?
A
~0.2mm
10
Q
Why stain tissue?
A
To enhance contrast in cell and be able to identify structures
11
Q
What are tissue components that stain with basic dyes called?
A
Basophillic
12
Q
What are tissue components that stain with acidic dyes called?
A
Acidophilic
13
Q
What are examples of basic dyes?
A
Toluidine blue, methylene blue, and hematoxylin
14
Q
What are examples of acidic dyes?
A
Eosin and fuchsin
15
Q
Are DNA and RNA acidic or basic?
A
Acidic
16
Q
In general, what can you see in a LM section?
A
Only cell, nucleus, and nucleolus / cannot see organelles
17
Q
In Trichrome stain, _______ always stains blue/green.
A
Connective Tissue
18
Q
What chemicals make up a Golgi stain?
A
Potassium dichromate and silver nitrate
19
Q
What does Sudan Black stain?
A
Lipids (aka adipocytes)
20
Q
What does periodic acid schiff (PAS) reaction stain magenta?
A
Carbohydrates (glycoproteins, goblet cells, etc. )
21
Q
What color does hematoxylin stain?
A
Blue
22
Q
What color does eosin stain?
A
Pink
23
Q
Is the mitochondria acidic or basic?
A
Basic
24
Q
What is a parenchyma?
A
Functional tissue of an organ
25
What is the use of fluorescent immunochemistry?
to identify proteins in cell and tissues
26
What is an epitope?
Area recognized by the antibody
27
What are the steps of Fluorescent Immunochemistry?
1) Identify cell with target antigen
2) Incubate tissue with primary antibody that binds to epitope
3) Incubate with secondary antibody that binds to primary antibody with a fluorescent tag
4) See under microscope
28
This dye is responsible for staining carbohydrates is...
Periodic Acid Schiff Reaction
29
Concept of plane of section
Where you cuts affects what you see
30
What is a transmission electron microscope?
Electron beam passed through very thin section of tissue
31
Dark areas in a TEM are called....
Electron dense
32
Light areas in a TEM are called...
Electron Lucent
33
What is a scanning electron microscope (SEM)?
Electron microscope that shows the 3D surface of a cell (more depth than TEM)
34
Electron microscopy uses what dye?
Osmium tetroxide
35
What is the nucleus?
Archive of the cells that produces informational molecules
36
Differentiate between euchromatin and heterochromatin
Euchromatin is light part and active DNA
Heterochromatin is dark part and inactive DNA
37
Which type fo DNA is transcribed into mRNA?
Euchromatin
38
What type of cisterna separates the inner nuclear envelope from the other nuclear envelope that bears ribosomes?
Perinuclear cisterna
39
What helps support the nucleus and aids in maintaining its shape?
LAMINS
40
What are lamins?
Support structures of intermediate filaments that "coat" the inner surface of the nucelar membrane and where chromosomes attach (nuclear lamina)
41
How does DNA fit in a nucleus?
DNA wraps around histones to fit in a helical coil of nucleosomes
42
DNA coiled around a histone is called a ________
Nucleosome
43
Characteristics of a nucleolus
- spherical
- acidic (basophilic)
- contains proteins and rRNA
44
What structure allows for transport in/out nucleus
nuclear pores
45
Nuclear pores require what type of transport for molecules over 9nm?
ACTIVE
46
Nuclear pores are made of...
proteins
47
Macromolecules transport across NPCs through a ____ pore
Aqueous
48
Nuclear localization signal on proteins is recognized by...
Nuclear import receptor (NIR)
49
How does cargo protein move through the nuclear pores?
- Nuclear import receptors (NIR) binds to nuclear localization signals (NRS) and to fibrils of the NPC
- Cargo moves through the pore by binding and dissociating again to proteins that line nuclear pore
- Inside nucleus NIR dissociates from cargo and returns to cytosol
50
Cisternae Defintion
A fluid-containing sac or cavity bounded by membrane (in ER and Golgi)
51
Lamellar Definition
Sheets stacks adjacent to each other with fluid or matrix in between
52
Cristae vs. Cisternae
Cristae are foldings of the inner mitochondrial membrane, while Cisternae are flattened structures of ER and Golgi
53
Lamellar and cristae serve what purpose in the mitochondria
Increase surface area
54
Which membranes of the mitochondria are restrictive versus permeable?
Outer membrane is permeable
Inner membrane is very restrictive
55
Mitochondria are located where in the cell?
Where energy requirements are high in the cell
56
Mitochondria undergo _____.
Fission
57
What percent of mitochondria uses its own DNA for proteins?
20% --> believed to be derived from bacteria
58
Is DNA synthesized in the mitochondrion independent of nuclear DNA?`
mitochondrial DNA is independent of nuclear DNA
59
Both mitochondria and endoplasmic reticulum are involved in ...
uptake, storage, and release of calcium
60
Where are enzymes stores in mitochondria?
on membranes of cristae
61
Mitochondria and peroxisome are both involved in...
Beta oxidation of long chain fatty acids
62
Which two structures in cell are involved in beta oxidation of long chain fatty acids?
mitochondria and peroxisome
63
What are functions of the mitcochondria?
- energy production (chemical energy to ATP)
- beta oxidation of long chain fatty acids
- uptake, storage, and release of calcium
- steroid hormone synthesis (side chain cleavage)
64
More cristae means more...
more surface area for energy production --> needed in cells that require large amounts of energy
65
All steroids are derived from...
cholesterol
66
1st step of steroid hormone synthesis is...
Side chain cleavage of cholesterol which happens in mitchondria
67
What enzyme is involved in side chain cleavage on the inner mitochondrial membrane?
Desmolase
68
What is the role of calcium granules in the mitochondria?
help regulate function (ATP production)
69
Side chain cleavage ends with what molecule?
Pregnenolone
70
What is pregnenolone?
precursor to certain steroids (progesterone, aldosterone, testosterone, etc.)
71
Which organelle synthesizes steroid hormone after side chain cleavage?
Smooth ER
72
Ribosomes are the site of...
protein synthesis
73
Which part of the mitochondria is responsible for TCA cycle?
Matrix
74
What is the purpose of the calcium granule?
to increase ATP production
75
Where is the side of side chain cleavage?
Inner mitochondrial membrane
76
RER is continuous with what two structures?
Nuclear envelope and SER
77
RER is full of ...
ribosomes that connect with perinuclear cisternae
78
RER stains what color?
Blue
RER stain intensely with basophilic dyes such as hematoxylin because it is acidic
79
What are polyribosomes and where are they found?
ribosomes associated with mRNA, which occur in cytosol or RER membranes
80
What are the functions of the RER?
Protein synthesis
81
Constitutive vs regulated secretion definition
Constitutive = occurs all the time
Regulated = needs signal to secrete
82
What is the function of secretion granules and where are they located?
Storage for proteins and are usually at apex of cell until needed
83
What are the functions of SER?
- Steroid Synthesis
- uptake and release of calcium in muscle cells (sim to mitochond)
- synthesis and breakdown of glycogen
- detoxification of drugs
- formation of lipoproteins
- production of bile
84
SER is abundant in which tissues?
cardiac and skeletal muscle cells
85
What is the function of the golgi complex?
post-translational protein modification (ex. glycosylation, sulfation, etc)
86
In the Golgi complex, proteins and lipids enter in the _____ and exit through the _____
enter cis face; exit trans face
87
Which stain do you use to identify cis face of Golgi?
osmium reduction
88
Which stain do you use to identify trans face of Golgi?
acid phosphatase
89
What happens if a protein does not work?
Proteasomes break it down
90
what is the importance of glycosylation?
correct folding of protein, protect from degradation, and signaling
91
What are lyosomes?
membrane bound organelles that degrade worn out structures in cell
92
Are lysosomes heterogeneous or homogenous in content?
heterogeneous
93
What are functions of lysosome?
degredation of bacteria, degrading worn out organelles, break down of bone during bone remodeling
94
How are lysosomes formed?
1) hydrolytic enzymes are formed in RER
2) enzymes have terminal mannose-6-phophate marker (M6P) added at Cis-Golgi
3) packaged at Trans-Golgi
4) vesicles are now early endosomes --> fuse with other vesicles to form late endosomes/lysosomes
95
Lysosomes contain what type of enzymes?
Hydrolytic
96
Lysosome enzymes are only found in what kind of environment?
ACIDIC
97
Definition of senescent cell
Dying cell
98
Lysosomal membrane contains a ____ which maintains the acidic interior of the organelle
proton pump
99
What in the lysosome keeps it from oxidizing its environment?
phospholipid bilayer
100
If bone formation decreases, leads to...
osteoporosis - bones become weak and brittle
101
if bone formation increases, leads to...
osteopetrosis (bones growing abnormally)
102
What is an example of a lysosomal storage disease?
Tay Sach's Disease: fatty substance build up in the brain
103
What are symptoms of Tach Sach's disease?
- neuromuscular symptoms
- absence of beta-hexosaminidase enzyme
slower growth in children
- bone-joint deformaties
- enlarged internal organs
104
Proteasomes recognize proteins with what kind of molecules?
Ubiquitin
105
What are proteasomes?
organelles that deal with proteins as individual molecules and aren't membrane bound
EDIT: NOT AN ORGANELLE! (complex of proteins)
106
What is ubiquitin?
marker of correct folding for proteasome to reognize
107
Are peroxisomes organelles?
NO they are MICROBODIES
108
What enzymes do peroxisomes contain?
oxidative enzymes and catalase
109
What are functions of peroxisomes?
Lipid metabolism (beta oxidation of long chain fatty acids) and degradation of hydrogen peroxide
110
How are peroxisome enzymes made?
protein made by RER and goes directly to peroxisome NOT through Golgi
111
What disease results from no beta-oxidation of FA in peroxisomes?
Zellweger's Syndrome
112
What causes Zellweger's Syndrome?
Enzyme made but not importing properly that causes babies to have high levels of low density glycoprotein
113
What are symptoms of Zellweger's syndrome (Cerebrohepatorenal syndrome)?
- muscle and nerve damage
- babies are hypotonic (can't hold themselves up)
- cause breakdown of myelin --> causes accumulation of toxic sub
- inability to nurse properly
- rare, autosomal
114
What are examples of inclusions?
Glycogen, lipofusion, lipid droplets
115
Where is glycogen enzymes synthesized?
SER
116
What is lipofusion?
yellow-brown pigment granules that accumulates with age (found in dying cells)
117
What are lipid droplets?
Lipid droplets are energy storage and a source of lipids which may be used in steroid hormone formation (not membrane bound)
118
What is the glycocalyx?
a carbohydrate sugar coat that surrounds the entire cells
- appears as fuzz on surface of microvilli
119
why do cells have membrane-bound compartments?
to maintain optimal concentration of biomolecules in/out of the compartments, provide a physical barrier, and separate to ensure specific processes can occur functionally
120
What is cytosol and what is in it?
fluid present in cell membrane (ions, H2O, proteins, etc.)
