Exam 1 Flashcards
(176 cards)
1
Q
What is cell biology?
A
The study of the structure and function of the unit of living organisms
2
Q
What are the three strands of cell biology?
A
Cytology
Biochemistry
Genetics
3
Q
What is cytology?
A
Focus mainly on cellular structure and emphasizes optical techniques
4
Q
What is biochemistry?
A
Focuses on cellular structure and function
5
Q
What is genetics?
A
Focuses on information flow and heredity
6
Q
What is the biggest asset to cytology?
A
Microscopy
7
Q
Micrometer is
A
one millionth (10^-6)
8
Q
What cells are a few micrometers in diameter?
A
Bacterial cells
9
Q
About how big are organelles?
A
The size of bacterial cells (1-2 micrometers)
10
Q
The nanometer is used for
A
molecules and subcellular structures too small for the light microscope
11
Q
The nanometer is
A
one billionth of a meter (10^-9_
12
Q
The earliest microscope was the
A
Light Microscope
13
Q
The light microscope allows for the identification of
A
nuclei, mitochondria, chloroplasts
14
Q
______ microscopy is also called brightfield microscopy
A
Light microscopy
15
Q
Light microscopes can identify structures by
A
passing a white light directly through a specimen
16
Q
The microtome
A
cuts specimens into thin slices
17
Q
What is limit of resolution?
A
How far apart objects must be to appear distinct
18
Q
The smaller the microscopes limit of resolution, the greater its
A
resolving power
19
Q
What are the four specialized light microscopes?
A
Phase contrast
Differential interference
Fluorescence
Confocal
20
Q
Fluorescence microscopy detects
A
proteins, DNA sequences, mlcs made fluorescent by binding to antibodies
21
Q
What is an antibody?
A
protein that binds to a particular target molecule called an antigen
22
Q
What does GFP allow us to do?
A
Study the temporal and spatial distribution of proteins in a living cell
23
Q
How does confocal microscopy work
A
Uses a laser beam to illuminate a single plane of a fluorescently labeled specimen
24
Q
Can you use GFP in living or nonliving cells?
A
LIVING
25
How does the electron microscope work?
Aims a beam of electrons rather than light through a specimen
26
The limit of resolution of electron microscopes is about ____ times better than light microscopes
100
27
What is the total magnification of electron microscopes?
100,000X
28
In transmission electron microscopy
Electrons are transmitted through the specimen
29
In scanning electron microscopy
the SURFACE of a specimen is scanned while electrons deflect
30
Who demonstrated yeast extracts could function?
The Buchners
31
What did the Buchners discovery lead to?
Discovery of enzymes
32
Who coined the 1 gene-1 enzyme hyopothesis
Beadle and Tatum
33
What is the 1 gene-1 enzyme hypothesis
One gene makes one protein in bacteria (wrong for humans)
34
Flemming identified
Chromosomes and mitosis
35
Morgan identified
Link traits to chromosomes
36
The genetic strand evolution goes mendel flemming to morgan meaning
physical traits are inherited (mendel) to nature of chromosomes (flemming) to traits belonging to parts of chromosomes (morgan)
37
Who proposed the double helix model?
watson and crick and franklin
38
Who coined the central dogma of molecular biology
Crick
39
What is the central dogma of biology?
DNA replicates itself by transcribing the RNA that is then translated to protein
40
What are the three important kinds of RNA molecules?
mRNA
rRNA
tRNA
41
What is mRNA
translated to produce protein
42
What is rRNA
components of ribosomes
43
What is tRNA
bring appropriate amino acid for protein synthesis
44
Recombinant DNA technology uses
restriction enzymes to cut DNA at specific places
45
Recombinant DNA technology allows scientists to create ________ with DNA from different sources
recombinant DNA molecules
46
What is DNA cloning?
Generation of many copies of a specific DNA sequence
47
What is DNA transformation?
process of introducing DNA into cells
48
Which microscopic technique would work best for precisely visualizing the location of a protein in a living cell?
Confocal microscopy with a fluorescently tagged protein
49
If you wanted to study the expression of many genes in a cell type and you wanted to study them simultaneously at the level of protein expression, what would you need to use?
Proteomics
50
Compare Direct and Indirect Immunofluorescence
Direct: not commonly used, antibodies bind to antigen
Indirect: more common, use 2 antibodies
51
What are some drawbacks to indirect immunofluorescence?
Requires specific antibodies
| Can't be done on living cells
52
What are the macromolecules of the cell
Proteins
Nucleic Acids
Polysaccharides
Lipids
53
What are the 9 classes of protens?
```
Enzymes
Structural
Motility
Regulatory
Transport
Signaling
Receptor
Defensive
Storage
```
54
What are enzymes
serve as catalysts and aim to increase rates of chemical reactions
55
What are structural proteins
Physical support and shape
56
What are motility proteins
Contract andmove
57
What are regulatory proteins
control and coordinate cell function
58
What are transport proteins
move substances in and out of cells
59
What are signaling proteins
communication between cells
60
What are receptor proteins
Enable cells to respond to chemical stimuli from the environment
61
What are defensive proteins?
Protect against disease
62
What are storage proteins
reservoirs of amino acids
63
How many amino acids are there? How many are used in protein synthesis?
60 total
| 20 used
64
What is the structure of amino acids?
R group
Amino group
Carboxyl group
65
Amino acids exist in L- or D- forms, but only ___ exist in proteins
L-
66
Each peptide has directionality: N terminus (_____) and C terminus (_____)
left
| right
67
How many amino acids have nonpolar hydrophobic R groups?
Nine
68
How many amino acids have hydrophilic R groups that are polar or charged?
Eleven
69
Acidic amino acids are _____ charged
Negatively
70
Polar amino acids tend to be found
On surfaces of proteins
71
Amino acids are linked together stepwise into a linear polymer by
Dehydration reactions
72
A peptide bond (C--N) forms as
H2O is removed
73
What is a peptide bond?
Carbon bound to nitrogen
74
The N-terminous group has a
amino group
75
The C terminous group has a
Carboxyl group
76
What is protein synthesis?
Process of elongating a chain of amino acids
77
The immediate product of amino acid polymerization is
a polypeptide
78
______ proteins consist of 2 or more polypeptides
Multimeric proteins
79
Proteins composed of 2 polypeptides are called
Dimers
80
Hemoglobin is a ____ consisting of 2 alpha subunits and 2 beta subunits
tetramer
81
Covalent disulfide bonds form
Between the sulfur atoms of two cysteine residues
82
How do disulfide bonds form?
Removal of 2 hydrogen ions (via oxidation) and can be broken by addition of 2 hydrogens (reduction)
83
What is the purpose of disulfide bonds?
To create considerable stability to the protein conformation
84
_______ form between cysteines in the same polypeptide
Intramolecular Disulfide bond
85
_______ form between cysteines in two different polypeptides
Intermolecular disulfide bonds
86
What are noncovalent bonds and interactions?
Hydrogen bonds
ionic bonds
van der waal
hydrophobic
87
Which is weaker: cysteine or noncovalent bonds?
Noncovalent bonds
88
How do hydrogen bonds form?
In water between amino acids via their R group
89
How do ionic bonds form?
Between positively and negatively charged R groups
90
Changes in pH can disrupt what type of bond?
Ionic
91
How do Van Der Waals Interactions form?
2 dipoles attract if they are close enough
92
What is a hydrophobic interaction?
When hydrophobic molecules are excluded from interactions with water.
93
What are the four levels of organization of protein structure?
Primary
Secondary
Tertiary
Quaternary
94
What makes up the primary stage of proteins?
Amino acid sequence
95
What makes up the secondary stage of proteins?
Alpha Helix and Beta Sheet, hydrogen bonding
96
What makes up the tertiary stage of proteins?
Different bonds and interactions
97
What makes up the Quaternary stage of proteins?
When multiple polypeptides are put together
98
What is the alpha helix?
Peptide backbone, spiral, R groups jut out from the spiral
99
How many amino acids per turn of the alpha helix?
3.6 amino acids
100
If the parts of polypeptides forming the beta sheet have opposite polarity they are called
antiparallel
101
What amino acids tend to form alpha helices?
Leucine
Mthionine
Glutamate
102
What amino acids tend to form beta sheets?
Isoleucine
Valine
Phenylalanine
103
What are motifs?
Short stretches of alpha helices and beta sheets in secondary structures
104
What are the two common examples of motifs?
B-a-B
Hairpin loop
Helix-turn-helix
105
What is the most stable conformation of a particular polypeptide?
It's Native Conformation
106
Proteins aredivided into what two categories
Fibrous
| Globular
107
Fibrous Proteins have
extensive regions of secondary structure giving them a highly ordered, repetitive structure
108
What are some examples of fibrous proteins?
Keratin
Fibroin
Collagen
Elastin
109
Most proteins are _____ folded into compact structures
Globular proteins
110
Most enzymes are what type of proteins?
Globular proteins
111
What is a domain?
Discrete, locally folded unit of tertiary structure, usually with specifi function
112
What is the structure of a domain?
50-350 amino acids long
| regions of a helix and b sheet mixed together
113
What is the function of nucleic acids?
To store, transmit, and express genetic information
114
Dna serves as the _______ of genetic information whereas RNA serves the role of ______ that information
repository
| expressing
115
_____ contains 5 carbon sugar Ribose
RNA
116
What are the Pyramidines?
(Pyramids, swords, cut)
| Cytosine, uracil, thymine
117
What are the purines?
Guanine, adenine
118
A nucleoside is
The sugar base portion without the phosphate group
119
Nucleic acids are linear nucleotides linked together by a
3' 5' phosphodiester bridge
120
_____ is a fundamental property of nucleic acids
Base pairing
121
Glycogen is highly
Branched
122
Starch occurs as both unbranched ______ and branched _______
amylose
| amylopectin
123
Cellulose is found in
plant cell walls
124
Why can't humans digest cellulose?
Lack an enzyme to break the beta glycosidic bonds
125
What are the 2 structural abnormalities of alzheimer's?
- amyloid plaques
| - Neurofibrillary tangles
126
What are amyloid plaques?
Made of mainly Amyloid beta, accumulate at synapses
127
What are neurofibrillary tangles?
Tau protein excessively phosphorylated to the point of tangled
128
What animal mutant genes are subject to therapy to reduce alzheimer's symptoms?
BACE 1
129
What are polysaccharides and their function?
Long polymers of sugars
| Serve in structure and storage
130
Aldo sugars have a ____ carbonyl group and Keto sugars have a _____ carbonyl group
terminal
| internal
131
For every molecule of CO2 incorporated into a sugar, one _____
water molecule is consumed
132
What is the most stable form of glucose?
D-glucose in Haworth projection
133
What are the two ring forms of D glucose?
Alpha (hydroxyl group down)
| Beta (hydroxyl group up_
134
What are the 3 disaccharides?
Maltose
Lactose
Sucrose
135
Disaccharides are linked via a ________
glycosidic bonds
136
What 2 disaccharides have an alpha glycosidic bond?
Maltose and Sucrose
137
What are the 2 storage polysaccharides?
Starch
| Glycogen
138
What are the 2 types of cells?
Prokaryotes (bacteria)
| Eukaryotes (plants, animals, fungi, algae, protozoa)
139
What distinguishes a prokaryote from a eukaryote?
Membrane bound nucleus in eukaryotes
140
Prokaryotic cells are divided into what 2 classes?
Bacteria and Archaea
141
What the 3 domains?
Archaea
Bacteria
Eukarya
142
What are examples of bacteria?
E. Coli
Pseudomonas aeruginosa
Strep
143
What are examples of archaea?
methanogens
Halophiles
Thermacidophiles
144
What are methanogens?
Obtain energy and convert CO2 to methane
145
What are halophiles?
Occupy salty environments
146
What are thermacidophiles?
Thrive in acidic hot springs
147
Cells specialized for _____ have characteristics to maximize their surface area (Ex. microvilli)
absorption
148
Many molecules move through cytoplasm by
Diffusion: regions of high to low concentration
149
Rate of _____ of molecules decreases as the _____of the molecule increases
diffusion
| increases
150
How do eukaryotic cells avoid slow diffusion rates?
By using carrier proteins
151
A eukaryotic cell has
membrane bound nucleus
152
A prokaryotic cell has
genetic information stored in a nucleoid
153
How do eukaryotic cells exchange materials between compartments within the cell and the exterior of the cell?
Exocytosis and endocytosis
154
Bacterial DNA is present in the cell in
circular form
155
Eukaryotic DNA is present in the cell in
Linear molecules
156
What is a histone
Linear molecules complexed with large amounts of proteins
157
Archaeal DNA is
circular and has protein similar to histones
158
Eukaryotic cells have how much more DNA than prokaryotes?
1000 times
159
How do bacterial and archaeal cells repllicate?
Replicate DNA and divide by binary fission
160
How do Eukaryotic cells replicate?
Replicate DNA and distribute chromosomes via mitosis and meiosis followed by cytokinesis
161
Chromosomes are difficult to visualize during ______ because they are dispersed as chromatin
interphase
162
What is the nucleoli?
harbors ribosomal DNA and synthesizes ribosomal RNA
163
The inner mitochondrial membrane
encloses the matrix (semifluid material filling mitochondria)
164
What is found in cristae?
Enzymes and intermediates needd for oxidation of sugars and generation of ATP
165
Chrloroplast is
The site of photosynthesis in plants and algae
166
What are thylakoids?
Membraneous sacs flattened and stacked into granum
167
Reactions involved in the reduction of CO2 to sugar occur within the
Stroma
168
Cisternae are
tubular membranes found in the ER
169
What is the internal space of the ER called?
Lumen
170
Smooth ER is involved with
synthesis of lipids and steroids
| inactivating and detoxification
171
What does the Golgi apparatus do?
processes and packages secretory proteins
172
Once processed by the Golgi complex, materials are packaged into
secretory vesicles
173
How do secretory vesicles work?
Move to plasma membrane andfuse with it to release contents outside of the cell
174
What makes up the endomembrane system of the cell?
ER
Golgi Apparatus
Secretory Vesicles
Lysosomes
175
What are peroxisomes and where are they found?
single membraned perform variety of functions found in liver and kidney cells
176
H2O2 is toxic but cells can be formed into water and oxygen by the enzyme
catalase
