Cell Biology Final Exam FA21 - PART I (CH1, 2, 4) Flashcards
Intro to cells Chemical Comp of Cells Protein Structure and Function
1
Q
What is the cell theory?
A
Cells come from pre-existing cells
2
Q
Who is responsible for the cell theory?
A
Rudolf Virchow
3
Q
What are the three domains?
A
Archaea, Eubacteria, Eukarya
4
Q
Which domains are closely related to each other?
A
Eukarya and Archaea. Bacteria evolved first.
5
Q
What is the evidence for Eukarya and Archaea being closely related?
A
Similarities in RNA polymerase (8-12 subunits) and resistance to antibiotics.
6
Q
Archaea:
- Nucleus
- Membrane-Bound Organelles
- Cell Wall
- Starting AA & Protein Synthesis
- RNA poly
- Ribosomes
- Sensitivity to antibiotics
- Fatty Acid Linkages
- Chromosome
- Translation
A
- Nucleus: Absent
- Membrane-Bound Organelles: None
- Cell Wall: Protein/Sugars
- Starting AA & Protein Synthesis: Met
- RNA poly: 8-12 Subunits
- Ribosomes: 70s
- Sensitivity to antibiotics: No
- Fatty Acid Linkages: Ether
- Chromosome: Single, circular
- Translation: mRNA translated into proteins
7
Q
Eubacteria:
- Nucleus
- Membrane-Bound Organelles
- Cell Wall
- Starting AA & Protein Synthesis
- RNA poly
- Ribosomes
- Sensitivity to antibiotics
- Fatty Acid Linkages
- Chromosome
- Translation
A
- Nucleus: Absent
- Membrane-Bound Organelles: None
- Cell Wall: Peptidoglycan
- Starting AA & Protein Synthesis: fMet (formulated)
- RNA poly: 4 subunits
- Ribosomes: 70s
- Sensitivity to antibiotics: Yes
- Fatty Acid Linkages: Ester
- Chromosome: Single, Circular
- Translation: Occurs at 5’ end of mRNA is synthesized.
8
Q
Eukarya:
- Nucleus
- Membrane-Bound Organelles
- Cell Wall
- Starting AA & Protein Synthesis
- RNA poly
- Ribosomes
- Sensitivity to antibiotics
- Fatty Acid Linkages
- Chromosome
- Translation
A
- Nucleus: Present
- Membrane-Bound Organelles: Present
- Cell Wall: Polymers sugar (cellulose in plants)
- Starting AA & Protein Synthesis: Met
- RNA poly: 8-12 subunits
- Ribosomes: 80s
- Sensitivity to antibiotics: No
- Fatty Acid Linkages: Ester
- Chromosome: Multiple, linear
- Translation: mRNA is translated into proteins in Eukaryotes
9
Q
What are the characteristics of life?
A
Highly organized Homeostasis Reproduction Growth and Development Take energy and matter from the environment Respond to stimuli Adaptation
10
Q
What is necessary for life to emerge on a planet?
A
Liquid Water
Energy Sun
Carbon (basic unit)
11
Q
What is the NASA definition of life?
A
A self-sustaining chemical system capable of Darwinian Evolution
12
Q
What are the origins of Life/Cells? [steps]
A
- ) Formation of organic molecules in primitive earth atmosphere - Miller (1950) experiment
- ) Formation of macromolecules - AA, Sugars, nucleic acids
- ) Macromolecules direct their own synthesis
- ) Enclosure of self-replication RNA in membrane - Phospholipid Bilayer
13
Q
Describe the miller- Urey experiment
A
Simulate the atmosphere via gases to see what would happen when heat/lightning added, went 1 week
14
Q
Results of Miller - Urey experiment
A
Found nucleic acid and all 20 amino acids (building blocks)
15
Q
What gases were thought to be present in the early atmosphere?
A
H2O, CH3, NH3, H2, CO
16
Q
If O2 was present in the Miller - Urey experiment why would it not work?
A
It would oxidize organic molecules necessary for life
17
Q
What are the origins of Eukaryotic Cells?
A
Step 1: Acquisition of a Membrane
○ Mitochondria
○ Chloroplast
■ Gave cell photosynthesis/cellular respiration, thought to be once free-living bacteria
- Development of multicellular organisms
○ 70s bacteria
○ 80s eukaryotic
18
Q
Describe the origin of the mitochondira and chloroplasts
A
Endosymbiotic theory
-Idea that mitochondria and chloroplast emerged from prokaryotic cells (like bacteria)
19
Q
Evidence of Endosymbiotic theory
A
Mitochondria and chloroplast have their own ribosomes and generate material in shape of circle (like bacteria)
Mito/Chloro also have two membranes - this shows absorption of Prokaryotic cell to Eukaryotic cell (relic)
20
Q
Description and Function: Nucleus
A
Stores DNA
Control, Genetic material storage
21
Q
Description and Function: Chromosomes
A
Histone help shape
Genetic info/coding
22
Q
Description and Function: Nuclear Envelope
A
2 membranes with nuclear pores
Let things in/out of nucleus
23
Q
Description and Function: Nucleous
A
Inside nucleus where stuff happens
Where RNA synthesis occurs
24
Q
Description and Function: Nuclear Lamina
A
Made up of fibrous material that give structure to nucleus
Gives structure to nucleus
25
Description and Function: Mitochondira
Double Membrane
Cristae: inner folds - ETC, ATP generation
Matrix: liquid material (Resp)
26
Description and Function: Chloroplast
Double Membrane
Stroma: Liquid material (calvin cycle)
Thylakoids: Disc like structures; light dependent reactions [photosynthesis]
27
Description and Function: Smooth ER
Nuclear envelope cont. connection with ER
| Where phospholipids ar made, carb metabolism, detox poisons
28
Description and Function: Golgi Apparatus
Stacked membrane
| Gets proteins from rough ER (where they are synthesized) modified through sugar residue so they go where they need to go
29
Description and Function: Lysosomes
Darker than peroxisomes
| Recycle center, proteins go to be degraded & some cellular structures
30
Description and Function: Peroxisomes
Lighter than lysosomes
| Any reactions requiring H2O2 occur here (so it is not toxic to cell)
31
Description and Function: Cytoskeleton
Made from globular proteins
Associated with Myosin and muscle movement
Connectional movement
32
Why do we use E. coli as a model organism?
- Prokaryote
- Amino acids/coding genetic info
- fundamental mechanisms of life
DISADVANTAGE: too simple for eukaryotic organisms
33
Why do we use Brewer's Yeast (Saccharomyces cerevisiae) as a model organism?
- Cell cycle decoded
- Find what controls DNA synthesis, mitosis, etc.
- Genes conserved in eukaryotes
34
Why do we use Arabidopsis thaliana as a model organism?
- close related to flowering plants
- plant models
- short life cycle
35
Why do we use Drosophila melanogaster as a model organism?
- Short life cycles
| - Examine development genes, gene transfer, movement of cells
36
Why do we use C. elegans as a model organism?
- Nematode worm
- adult form has 959 cells, 70% genes common in humans
- study development and apoptosis (aka in relation to cancer)
37
Why do we use Xenopus laevis as a model organism?
- Frog
- Large eggs to see development. Follow with naked eye
- Early development model
38
Why do we use Danio rerio as a model organism?
- Zebra fish
- Embryo transparent (look at vert. development)
- X linked model system to look at vertebrae development
39
List the functional groups (9) & Draw structures
1. Alcohol
2. aldehyde
3. ketone
4. carbonyl
5. ether
6. amino
7. phosphate
8. carboxyl
9. esters
40
What are the four groups of molecules found in cells?
1. Sugar
2. Lipids
3. Proteins
4. Nucleic Acids
41
What are the properties of water?
1. Universal Solvent
2. Cohesion/Adhesion
3. Solid water is less dense than liquid water
4. High specific heat capacity
5. High heat of vaporization
42
Water: Universal Solvent
Dissolves more substance than any other liquid. Can carry nutrients, minerals, chemicals
43
Water: Cohesion/Adhesion
Cohesion: stick to water (capillary action)
Adhesion: water sticks to non-water things, move against gravity
44
Water: Solid water is less dense than liquid water
Ice is less dense than liquid water so it floats
45
Water: High specific heat capacity
Can absorb a lot of heating without a significant rise in the temperature - stabilizes in climate systems
46
Water: High heat of vaporization
The energy needed to turn H2O to vapor - moderates temperature of ecosystem; prevents overheating
47
Macromolecules: Sugars - what are the types of sugars
1. Monosaccharides
2. Disaccharides
3. Polysaccharides
48
Monosaccharides
Energy storage and building blocks for larger sugar, glucose, mannose, galactose
49
Disaccharides
Quick energy storage, sucrose, lactose, maltose
50
Polysaccharides
Energy storage allows for changes in concentration gradient which influences the uptake of nutrients by H2O cells, starch, glycogen, peptidoglycan
51
What are the types of lipids?
1. Saturated FA
| 2. Unsaturated FA
52
Saturated Fatty Acids
No double bonds
better for packing
"straight"
53
Unsaturated Fatty Acids
Double bounds, less packing
| "kink"
54
Do Unsaturated FA or Saturated FA have more fluidity? Why?
There is more fluidity with unsaturated fatty acids because the double-bonded C’s cause
kinks in the hydrocarbon chain allowing for more space and fluidity
55
Amino Acids: Acidic
Acidic, Negative
Aspartate
Glutamate
Asp, D
Glu, E
56
Amino Acids: Basic
Basic, Positive
Lysine
Arginine
Histidine
Lys, L
Arg, R
His, H
57
Amino Acids: Uncharged Polar
```
Serine
Threonine
Cysteine
Asparagine
Glutamate
```
```
Ser, S
Thr, T
Cys, C
Asn, N
Gln, Q
```
58
Amino Acids: Non-Polar
```
Glycine
Alanine
Proline
Valine
Leucine
Isoleucine
Methionine
Phenylalanine
Tyrosine
Tryptophan
```
```
Gly, G
Ala, A
Pro, P
Val, V
Leu, L
Ile, I
Met, M
Phe, F
Tyr, Y
Trp, W
```
59
What are the nucleic acids?
DNA (ACTG)
| RNA (ACUG)
60
How is the shape of protein determined?
The shape of the protein is determined by protein folding - due to electrostatic interactions, hydrogen bonding, van der Waals, hydrophobic effect.
61
What are alpha and beta helices [shape and structure of proteins]
Result form H-bonds that form between the N-H and C double bounded O groups in polypeptide backbone
62
Beta sheets [shape and structure of proteins]
Run parallel or antibparallel
63
Primary protein structure [shape and structure of proteins]
sequence of a chain of AA
64
Secondary protein structure [shape and structure of proteins]
Occurs when the sequence of amino acids are linked by hydrogen bonds
65
Tertiary protein structure [shape and structure of proteins]
Occurs when certain attractions are present between alpha-helices and pleated sheets
3D structure
66
Quaternary protein structure [shape and structure of proteins]
Protein consisting of more than one amino acid chain
| Subunits - ex. hemoglobin
67
What are disulfide bonds?
| [Covalent cross linkages]
Stabilize protein against unfolding and dissociation (cysteine)
68
What are intermolecular bonds?
Between SEPERATE proteins
69
What are intramolecular bonds?
Between the SAME proteins
70
Briefly describe prions.
● Single protein
● No genetic material
● Mostly brian diseases
● Cause a misfolding in a protein
71
What is Kuru? Describe and list
■ Characterized by shaking and trembling and eventual loss of muscle
control
■ Brain material showed brains filled with vacuoles and cavities, presenting
a sponge-like appearance
■ The disease presents no signs of inflammation, elevated temperature, or
antibody production
■ Gadjusek and Zigas began to assume that the disease was caused by a newly identified group of viruses called slow viruses
72
Prions and Sheep. Describe
■ William Hadlow recognized similarities between scrapie and kuru
■ Infected sheep with scrapie developed seizures, shakes, and paralysis
■ Hadlow demonstrated that brains of normal sheep with injected with brains from scrapie-infected brains developed scrapie
■ These diseases were identified as transmissible spongiform encephalopathies (TSEs) due to brian’s sponge-like appearance
73
Prions and Mad Cow Disease. Explain
■ The TSEs show a long latency period from infection to illness and are
resistant to inactivation by ordinary methods
74
What is the prion hypothesis? Explain
■ Tikvah Alper showed that scrapie agent retained its infectivity even under
UV light - therefore lacks DNA and RNA
■ Identified a protein in scrapie brain that did not appear in the brains of
healthy animals PrP
■ The amino acid sequence for the cellular protein PrPc and the diseased
protein PrPsc were identical
■ The normal gene contains lengthy coils of a-helices, while the diseased
protein was an insoluble aggregate consisting of B-pleated sheets
■ The misfolded Prpsc protein acted as a template and forced the
misfolding of the normal PrPc protein
■ Stanley Prusiner - discovered prions
75
What is Bovine Spongiform Encephalopathy (BSE)? Explain
Mad cow disease.
■ Cattle became infected from contaminated feed
■ Changes in feed involved incomplete exposure to heat as well as eliminating the exposure of the rendered meat to hydrocarbon solvents under steam
76
Sickle Cell Anemia. Describe
Gene/ Protein: Glu6Val, Hemoglobin
Mutation: Missense
Symptoms: Can’t carry O2 as well, change in cell membrane=weakening more fragile, can break open easier sores on extremities, risk for heart disease
77
Marfan Syndrom. Describe.
Gene/ Protein: A705T, Fibrillin-1
Mutation: Missense
Symptoms: Longer limbs, loose joints, dissociation of eye, structure of aorta= compromised, aorta rupture
78
Phenylketonuria
Gene/ Protein: Arg408Trp, Phenylalanine Hydrolase
Mutation: Missense
Symptoms: Intellect disability-> preventable
79
Neurofibromatosis
Gene/ Protein: NF-2, Merlin (tumor suppressor)
Mutation: Missense
Symptoms: Tumors form @nerve endings
80
Retinoblastoma
Gene/ Protein: RB1, pRB
Mutation: Nonsense
Symptoms: Tumor on retina-> children
81
Huntington’s
Gene/ Protein: Htt, Huntington
Mutation: Insertion
Symptoms: Progressive breakdown of nerves, fatal, 1st gene looked at in human genome
82
Progeria (Hutchinson’s)
Gene/ Protein: Gly608Gly, cystine w/ thymine @position 1824
Mutation: Deletion
Symptoms: Lamin gene is not stable, weakens cell structure, premature death & aging
83
What is competitive inhibition?
substances that resemble normal substrate competes with substrate for active site
Example:
(sulfa drugs work by inhibiting an enzyme responsible for synthesis of folic acid-> interact w/ active site to inhibit folic acid formation)
84
What is allosteric inhibition?
binds to another site and changes shape of active site
85
What is phosphorylation?
Phosphate group binds to molecule, puts full (neg) charge on protein, transfers phosphate group from ATP to protein
86
What are GTP binding proteins?
GTP= active conformation on
GDP= inactive
GTP-> GDP releases a phosphate
