Lecture Anatomy 2 Flashcards
1
Q
Robert Hooke
A
- The father of microscopy
- Coined term “cell” to describe the basic unit of life
2
Q
Mattias schleiden and Theodore schwann
A
- All living things are composed of one or more cells
3
Q
Hierarchy of life
A
- Tracing life down to the chemical level: the hierarchy of biological organization
- Ecosystem -> community -> population -> organism -> organ system -> organ -> tissue -> cell -> molecule -> atom
4
Q
- Morphology of cells
A
o Different Sizes and shapes of cells
o Different function
o Structure determines function
5
Q
- Cells differ in
A
o Ability to move
o Internal organization (prokaryotic versus eukaryotic (function)
o Metabolic activities (chemical reaction)
6
Q
- Cells share
A
o Certain structural features and carry out many complicated process in basically the same way
7
Q
Are the following organic molecules alive?
- Proteins, carbohydrates, lipids, and nucleic acids
A
o No
8
Q
Cell theory
A
- All organisms are composed of cells and cell products
- All cells come from Previously existing cells
o Parent cell to two daughter cells (identical)
9
Q
All organisms are composed of?
A
- Cells and cell products
10
Q
Are all of the cells within an organism the same?
A
- No
11
Q
How many distinct cell types make up the human body?
A
- 210
12
Q
Life begins with?
A
- Cells
- Each cell performs all the functions necessary to sustain life
13
Q
We all developed from?
A
- A single-celled human zygote formed by fertilization
o Smaller than a period found in your text books
14
Q
- Zygote
A
o Eukaryotic cell formed by a fertilization event between two gametes
15
Q
- Zygote develops into?
A
o A full blown organism with 100 trillion cells organized into complex tissues and organs
16
Q
Two major categories of cells
A
- Prokaryotic cells and eukaryotic cells
17
Q
- Difference between prokaryotic and eukaryotic cells
A
o Prokaryotic has no nucleus and eukaryotic has
18
Q
o Prokaryotic cells:
A
only domains: bacteria and archea
Lacking nucleus
Simple cells
19
Q
o Eukaryotic cells:
A
plant and animal kingdoms, including the fungi (multicellular molds and unicellular yeast
Have nucleus
20
Q
What type of cells do humans have?
A
- Eukaryotic multicellular cells
21
Q
Different cell size?
A
- Different function
- Complexity of what they do
22
Q
Prokaryotic cells
A
- Consist of a single enclosed compartment that is surrounded by a plasma membrane
- Lacks a defined nucleus
23
Q
- Dna is located where in prokaryotic cells?
A
o Nucleoid region
24
Q
- What is the most numerous prokaryotes?
A
o Bacteria
25
- Bacteria
o Don’t have membrane bound compartments
| o Have many proteins that are precisely localized in their aqueous interior or cytosol
26
- Cytosol
o The fluid in which organelles of the cell resides
27
Eukaryotic cells
- Contain a defined membrane-bound nucleus that is absent in prokaryotes
- Nucleus segregates the cellular DNA for the rest of the cell
Eukaryotic organisms Can be unicellular or multicellular
28
- Nucleus
o Command center of cell
| o Contains genetic materials (RNA and DNA)
29
Three main parts of cells
- 1. Plasma membrane
- 2. The cytoplasm
- 3. The nucleus
30
Plasma membrane
- Defines the extent of cell
o Inside – intracellular
o Outside – extracellular
o Interstitial fluid between cells
- Separates the living cell from its nonliving surrounding
- Thing/flexible layer that separates the intracellular and extracellular compartments
31
What forms the plasma membrane?
- Molecule called phospholipids
- Phospholipid bilayers
- Hydrophilic head (outside cell)
- Hydrophobic tail (inside cell)
32
Phospholipids
- 2 fatty acid chains (tail = non polar or hydrophobic)
| - A phosphate group (head = polar or hydrophilic)
33
Membranes consists of?
- Proteins embedded in the phospholipid bilayer
- Proteins make up 50% of membrane mass
- A fluid mosaic of lipids and proteins
34
Fluid mosaic
- Membrane phospholipids and proteins can drift about in the plane of the membrane
35
“fluid”
- Molecules can move freely within the membrane
36
“mosaic”
- A diversity of proteins exists within the membrane
37
Proteins found in plasma membrane
- Integral membrane proteins – firmly embedded
| - Peripheral membrane proteins – loosely associated/not embedded
38
Integral membrane proteins
- Transmembrane
| - Span entire width of membrane and contain both hydrophilic and hydrophobic regions
39
Peripheral membrane proteins
- Don’t span entire membrane
| - Loosely associated with other proteins or lipid molecules
40
Functions of membrane
- Anchors the cells to form a common function
- Selective permeability
o Allow some substances to cross more easily than others (size or charge)
o Block passage of some substances altogether
- Provides barrier against substances outside the cell
- Some act as receptor for cellular communication
- Transport
- Intercellular joining
41
Diffusion
- Movement of molecules from higher concentration to lower concentrating across membrane
- Tend to spread into available space
- Passive transport; no energy is needed
42
Facilitated diffusion
- Transport of some substances by specific transport proteins that act as selective corridors
- Traffic of some substances can only occur through transport proteins
- Glucose- require transport protein
- Passive transport
43
Osmosis
- (diffusion) Passive transport of water across a selectively permeable membrane from higher concentration to lower concentration
44
Survival of the cell depends on?
- Ability to balance water uptake and loss
45
Solution
- Solute and solvent
- Solute – gets dissolved
- Solvent – water does the dissolving
46
Isotonic solution
- Equal concentration of ions in solution and cell
47
Hypertonic solution
- Higher concentration of ions in solution than in cell
47
Hypotonic solution
- Lower concentration of ions in solution than in cell
48
Osmoregulation
- Control of water balance animals
49
Endocytosis
- Mechanism by which particles enter cells
50
3 forms of endocytosis
1. Phagocytosis
2. Pinocytosis
3. Receptor-mediated endocytosis
51
Phagocytosis
- “cellular eating”
- Cell engulfs a particle and packages it within a food vacuole
- Most wbc
52
Pinocytosis
- “cellular drinking”
- Primarily used for absorption of extracellular fluids (ECF)
- Contrast to phagocytosis
o Generates very small vesicles
o Unspecific in the substances that it transports
53
- Receptor-mediated endocytosis
o Triggered by the binding of external molecules to membrane proteins
o Upon membrane proteins binding to certain molecules – membrane forms coted pit then pinch off to become coated vesicle (Low density lipoproteins or viruses
54
Exocytosis
- Mechanism that move substances (enclosed in a vesicle) out of the cell
- Vesicle migrates to plasma membrane
- Proteins from vesicle bind with membrane proteins
- Lipid layers from both membrane fuse
- Vesicle releases contents to outside of cells
55
Cytoplasm
- Cell-forming material
| - Part of cell that lies internal to the plasma membrane and external to the nucleus
56
3 major elements that make up the cytoplasm
- Cytosol
- Organelles
- Inclusions
57
Cytosol
- Jelly-like, fluid-containing substance within the cell
- Consists of water, ions, and enzymes
- Makes up half of the volume of the cytoplasm
- Fluid In which other cytoplasmic elements are suspended
58
Cytoplasm contains nine types of organelles
- Mitochondria
- Ribosomes
- Lysosomes
- Cytoskeleton
- Centrioles
- Golgi apparatus
- Rough and smooth er
- Peroxisomes
59
Ribosomes
- Constructed of proteins and ribosome RNA
- Site of protein synthesis
- Composed of two subunits (60s and 40s) that fit together to form a functional ribosome
60
Type of ribosomes found in the cell:
- Free ribosomes
| - Attached ribosomes
61
Free ribosomes
- Float in cytosol
| - Make soluble proteins (function in cytosol)
62
Attached ribosomes
- Attached to rough ER and make membrane proteins or exported proteins
63
Ribosomes build all the cell’s proteins though a process
called?
- ???
- Translation
64
Antibiotics target the process of the?
- Ribosomes
65
Endoplasmic reticulum (ER)
- Network within the cytoplasm
| - Extensive system of membrane-walled envelopes and tubes
66
Two distinct type of ER
- Rough ER
| - Smooth ER
67
Rough ER
- Ribosomes stud the external surfaces
- Envelope stacks called cisternae
- Makes all membrane proteins and membrane
68
Smooth ER
- Consists of tubules in a branching network
- No ribosomes are attached
- No protein synthesis
- Store Ca(2+)
- Makes enzymes for lipid metabolism
- Including steroids
69
After the rough ER synthesizes a molecule it?
- Packages the molecule into transport vesicles
70
Golgi apparatus
- Packaging and shipping center
- Stack of 3 – 10 disk shaped membrane bound envelopes (cisternae)
- Works in partnership with ER; sorts products of rough ER at the cis end and sends them to proper destination from the trans end
71
Mitochondria
- Power plant of the cell
- Generates most of the cell’s energy (AT) via cellular respiration
- Enclosed by a double membrane: the inner membrane folds in forming shelf-like cristae
- Contains own DNA (maternal DNA)
72
Lysosome
- spherical membranous bags containing digestive enzymes, “demolition crew” that break down macromolecules
73
secretory lysosome
- found in white blood cells, immune cells, and melanocytes
74
lysosome functions
- digest ingested bacteria, viruses, and toxins
- degrade nonfunctional organelles
- breakdown glycogen and release thyroid hormone
- breakdown non-useful tissue (webbing between fingers and toes during fetal development
- breakdown bone to release Ca(2+)
75
peroxisomes
- ubiquitous organelles in eukaryotes that participate in the metabolism of fatty acids and metabolites
- membranous sacs containing oxidases and catalaes: “toxic waste plants”
76
peroxisome function
- detoxify harmful or toxic substances
- break down long chains of fatty acids (numerous in the liver and kidneys)
- neutralizes dangerous free radicals and break down poisons
77
free radicals
- highly reactive chemicals with unpaired electrons
78
cytoskeleton
- cell skeleton
- consisting of a network of rods/fibers that run throughout the cytosol
- provides mechanical support to the cell and maintain its shape and provides machinery for various cellular movements
79
cytoskeleton provides three types of protein rods (not covered by membranes)
- microtubules
- microfilaments
- intermediate filaments
80
microtubules
- cylindrical structures made of proteins called tubulin
| - radiate from centrosome
81
- centrosome
o cell center
o organelles attach to and move along microtubules, which constantly assemble and dissemble
o thickest
82
microfilaments
- actin filaments
- filaments of contractile protein actin that interact with myosin to create cell division, perform endo- and exocytosis and play a role on pseudopod extension and retraction
- organelles also attach to and move along actin filaments which constantly assemble and dissemble
- thinnest
83
intermediate filaments
- protein fibers
- most stable and permanent
- help cells resist pulling forces
- provide tensile strength
- play a role in linking cells together
84
centrosomes
- spherical structure in the cytoplasm
- composed of centrosome matrix (outer cloud) and centrioles
- microtubules are anchored at the centrosome (microtubule organizing center)
85
centrioles
- paired cylindrical bodies forming a pinwheel array of nine triplets of microtubules = 27 short microtubules
- act in forming cilia and flagella
- organize mitotic spindle during mitosis
86
cilia
- motile appendage
- move in coordinated back and forth motion
- some extend from nonmoving cells
- human windpipe
87
flagella
- motile appendage
| - propel the cell in a whiplike motion
88
inclusions
- temporary structure that are not present in all cell types
| - may consist of pigments, crystals of proteins, and food store
89
- lipid droplets
o found in livers cells and fat cells and glycosomes
o glycosomes
store sugar in the form of glycogen = long chains of glucose
90
nucleus
- the central core or kernel
- control center of cell
- contains dna and directs the cells activities
- appr. 5um in diameter
91
nuclear envelope
- two parallel membranes separated by fluid filled space
92
nucleolus
- little nucleus
- in the center of nucleus
o conatins parts of several chromosomes
o site of ribosome subunit manufacture
93
nucleus contain chromatin
- dna in a cell Is packed into an elaborate, multilevel system of coiling and folding
94
DNA bonding
- purines: A and G
- Pyrimidines: C and T
- 3 hydrogen bonds between cytosine and guanine
- 2 hydrogen bonds between adenine and thymine
95
Chromatin composed of
- DNA and histone protein
96
Condensed chromatine contains
- Tightly coiled strands of DNA
97
Extended chromatin contains
- Uncoiled strans of DNA when DNA’s genetic code is copied onto mRNA
98
What is the highest level of organization of chromatic?
- Chromosomes
| o Contain a long molecule of DNA
99
How many chromosomes are there in a typical human cell?
- 46 chromosomes
100
DNA controls the cell by?
- Transferring its coded information into RNA
101
The information in the RNA is used to?
- Make protein
102
The cell theory states…????
>>>>
103
What is reproduction?
- The birth of a new organisms
| - Occurs much more often at the cellular level
104
FYI
- More cells in body than stars in milky way
| - Past second, millions of your cells have divided into two
105
Before development and differentiation of cells you must have?
- Cell division
106
Cell division plays a role in?
- The replacement of lost or damaged cells
- Cell reproduction and growth
- Some multicellular organism can divide into pieces that then grow into new individuals
107
Before a parent cell divides…
- It duplicates all of its genetic materials
108
After cell division
- the two resulting “daughter” cells are genetically identical
109
what is as genome?
- Organisms complete set of DNA including all of its gene
110
Genome is located mainly on?
- Chromosome in the cells nucleus
111
Chromosomes are made of?
- Chromatin
- Combination of DNA and protein molecules
- Are not visible in a cell until cell division
112
Before a cell divides, it duplicate all of its chromosomes, resulting in two copies called?
- Sister chromatids
113
What happens to the sister chromatids when the cell divides?
- Separate from each other
114
Cell cycle
- Eukaryotic cells that divide undergoes an orderly sequence of events
115
Cell cycle consists of two distinct phases
- Interphase (90%)
| - Mitotic phase (10%)
116
Interphase
- G1 – cell growth
- S phase – DNA synthesis; chromosome duplication
- G2
117
Mitosis
- The division of the chromosomes
| - Preceded by interphase G1 S G2
118
Four distinct phases of mitosis
- Prophase
- Metaphase
- Anaphase
- Telophase
119
Prophase
- Asters are seen
- Chromatin condenses into chromosomes attached to one another by their centromere (sister chromatids + prtoeins = kinetochore
- Nucleoli disappears
- Centriole pairs separate and mitotic spindle is formed
- Nuclear envelope disappears
- Microtubules attach to kinetochores and begin moving sister chromatid to center of cells
120
Metaphase
- Sister chromatids cluster at the middle of the cell with their centromeres aligned at the exact center
- Arrangement of chromosomes along a plane midway between the poles is called the metaphase plate
121
Anaphase
- Centromeres of the sister chromatids split and each becomes a chromosome again
- Motor proteins in kinetochores pull chromosomes towards poles
122
Telophase
- Reversal of prophase
- Cleans up the after effects of mitosis
- Corresponding sister chromosomes attach at opposite ends of the cell
- New nuclear envelope forms around each of separated sister chromosomes
- Both sets of chromosomes unfold back into chromatin
123
Mitosis is complete after prophase-metaphase-anaphase-telophase, but cell division has yet one more step to complete. What?
- Cytokinesis
124
Cytokinesis
- Occurs during telophase
- The division of the cytoplasm
- Not part of mitosis
- Mitosis ends at telophase
125
Normal plant and animal cells have a cell cycle control system…
- Series of checkpoints
126
- When cell cycle control system malfunctions
o Cells may reproduce at the wrong time or place
| o Benign tumor may form
127
What is cancer?
```
- A class of diseases in which a group of cells display the following characteristics
o Uncontrolled growth
o Invasion (intrusion on and destruction of adjacent tissues)
o Metastasis (spread to other locatioin in the body via lymph or blood
```
128
Cancer is caused by?
- Breakdown in control of the cell cycle
| - The cancerous cell ignores the cell checkpoints
129
Cancer cells?
- Divide excessively
| - Spread from a malignant tumor
130
Metastasis
- Spreading of cancerous cells
131
Cancer treantment
- Radiation therapy disrupts cell division
| - Chemotherapy involves drugs that disrupt cell division
132
Cancer research
- Cancer cells are often grown in culture for study
133
Cancer prevention and survival
- Changes in lifestyle
- Not smoking
- Avoiding exposur to the sun
- Eating a high-fiber, low-fat diet
- Visiting the doctor regularly
- Performing self-examination
134
Your body has how many different cell types?
- 210
135
Cellular diversity
- Specialized functions of cells relates to the shape of cells and the arrangement of organelles
136
Cells that conncet body parts or cover organs
- Fibroblast
- Erythrocyte (RBC)
- Epithelial cell
137
Fibroblast
- Makes and secretes protein component of fibers
138
Erythrocyte (RBC)
- Concave shape provides surface area for uptake of the respiratory gases
139
Epithelial cell
- Hexagonal shape allows maximum number of epithelial cells to pack together
140
Cells that move organs and body parts
- Skeletal and smooth muscle cells
o Elongated and filled with actiin and myosin
o Contract forcefully
141
Cells that store nutrients
- Fat cell (adipocyte_
| o Shape is produced by large fat droplet in its cytoplasm
142
Cells that fight disease
- Macrophage
| o Phagocyte that moves through tissue to reach infection sites
143
Cells that gather information
- Neuron
| o Has long processes for receiving transmitting messages
144
Cells of reproduction
- Oocyte
| - Sperm
145
Oocyte
- Female
- Largest cell in the body
- Contains many copies of organelles for distribution to daughter cells
146
Sperm
- Male
| - Possess long tail for swimming to the egg for fertilization
147
Youth
- Begin as a feritilized egg
- Cells in embryo are exposed to chemical signals that channel cells into specific pathways of development
- Cell specialization leads to structural variation of cell types
148
Aging
- A complex process casued by a variety of factors
- Free radical theory
- Mitochondrial theory
- Genetic theory
o Telomeres
o Telomerase
149
Free radical theory
- Damage from byproducts of cellular metabolism
| - Radicals build up and damage essential molecules of cells
150
Mitochondrial theory
- Decrease in production of energy by mitochondria weakens and ages our cells
151
Genetic theory
- Proposes that aging is programmed by genes
152
Telomeres
- End caps on chromosomes that limit the maximum number of time a cell can divide
153
Telomerase
- Prevents telomeres from degrading
154
chromatin
DNa + Histone (proteins)
155
nucleosome
- histone + dna combination without the linker DNA
156
linker DNA
between nucleosomes
157
heterochromatin
- condensed/packed chromatin
158
euchromatin
- extended/loose chromatin
159
DNA
double stranded helix
160
protein
amino acid + AA + AA
161
nucleotides
- form DNA strands
| - Purine and Pyrimidine
162
purine
adenine A
| Guanine G
163
pyrimidine
Thymine T
Cytosine C
(CUT - Pyramid)
164
nucleotide pairings
A-T (2 hydrogen bond)
| G-C (3 hydrogen bond)
165
autosome
- 22 copies of non-sex chromosome
166
sex chromosome
X + Y
167
TRisomy 21
3 copies of chromosome 21
| - downsyndrome
168
cellular division consists of
mitosis
| cytokenisis
169
why cell division
to repair
| cell growth
170
Gene
sequence of DNA that codes for functional protein or functional RNA
171
dna to protein process
DNA (transcription) -> RNA -> mRNA -> (Translation) Protein
172
centromere
middle center of sister chromatids
173
telomeres
end side of sister chromatids
174
homologous chromosomes
matching pairs
175
homologous pair from mom + dad identical?
not identical but similar
176
homologous chromosome of sister chromatids identical?
yes
177
ribosomes are composed of?
two subunits
- 40 small subunits
- 60 large subunits
178
is ribosome membrane bound?
no
179
what is the central dogma of molecular biology?
DNA -> RNA -> mRNA -> Protein
180
DNA to RNA
RNA to mRNA
mRNA to Protein
- transcription in nucleus
- post transcriptional modification in nucleus
- translation in cytoplasm
181
with in the attached ribosome, what happens to proteins being made
1. exocytosed
2. contained within a vesicle
3. embedded in the plasma membrane
182
which organelles contains cisternae?
- ER
- Golgi apparatus
- mitochondria
183
oxidase and catalase
oxidase convert free radicals to hydrogen peroxide
| catalase converts hydrogen peroxide to H2O +02
