Cell Bio Midterm Flashcards
1
Q
Micrometer
A
um
2
Q
Nanometer
A
nm
3
Q
Prokaryote
A
Unicellular, lacks membrane-bound nucleus, mitochondria, or any other membrane-bound organelle
4
Q
Eukaryote
A
Large, complex. cells have nucleus enclosed within membranes
5
Q
7 rules of cell
A
- 1) All organism are comprised of one or more cells.
- 2) All cells contain plasma membrane, cytoplasm, genetic material.
- 3) All cells store their heredity information in the same linear code (DNA).
- 4) All cells require energy to maintain and sustain life. Energy comes from nutrients
- 5) All cells can sense change in their surroundings and make appropriate changes.
- 6) Cells are highly complex and organized.
- 7) All cells come from pre-existing cells. (mitosis/meiosis)
6
Q
Carbon
A
most important biological molecule. can create diverse array of compounds, most commonly forms bonds with oxygen (O), hydrogen (H), nitrogen (N), and sulfur (S)
7
Q
Covalent bond
A
bond between two atoms to increase their stability. each covalent bond has 2 electrons
8
Q
4 classes of macromolecules
A
Protein, carbohydrate, lipid, nucleic acid
9
Q
Monomer
A
basic subunit, join together to form polymers (building blocks for macromolecules)
10
Q
Process of polymerization
A
Hydroxyl group + hydrogen group. results in H20 per bond
11
Q
Carbohydrate monomer
A
monosaccharide
12
Q
Carb polymer
A
polysaccharide
13
Q
Protein monomer
A
amino acid
14
Q
Protein polymer
A
polypeptide chain
15
Q
nucleid acid monomer
A
nucleotide (RNA)
deoxynucleotide (DNA)
16
Q
nucleic acid polymer
A
nucleic acid (RNA) deoxynucleic acid (DNA)
17
Q
lipid monomer
A
glycerol + fatty acids
18
Q
Lipid polymer
A
lipids
19
Q
Carbohydrate: general formula
A
Cm(H20)n or Cm H2n On
m= # of carbons
n=# of oxygen
#H = 2x # of oxygen
20
Q
Maltose bond
A
(alpha) 1,4 glycosidic bond
21
Q
Lactose bond
A
(beta) 1,4 glycosidic bond
22
Q
Examples of polysaccarides
A
starch, glycogen, cellulose
23
Q
Where do humans store carb energy?
A
Liver and muscles in form of glycogen
24
Q
Breaking bonds (storage of energy to usage of energy)
A
Hydrolysis
25
Creating bonds
condensation
26
covalent bond for carbs
glycosidic bond
27
Components in amino acids
Alpha carbon, hydrogen atom, amino group, carboxylic acid, amino acid side chain or "R group"
28
R group does not...
participate in creating peptide bonds
29
covalent bond for amino acids/proteins
peptide bond
30
3 groups of amino acids
a) Non-polar (hydrophobic)
b) Polar (uncharged)(hydrophilic)
c) Polar (charged)(hydrophilic)
31
Polypeptide polymerization
Amino terminus (N-terminus) to carboxyl terminus (C-terminus)
32
What do polypeptides need to do to become proteins
be folded
33
3 traits of proteins
1) all proteins adopt AT LEAST two stable 3D shapes
2) all proteins bind to at least one molecular target
3) all proteins perform at least one cellular function
34
4 levels of protein structure
1) Primary: linear sequence of amino acids, covalent peptide bonds
2) Secondary: initial folding of polypeptides. alpha-helix and/or beta-sheet
3) Tertiary: 3D shape of protein, functional for monomeric, not function for dimeric or multimeric
4) Quaternary: Applies only to >monomeric (di & multimeric become functional)
35
Disulfide bond
formed by cysteine side chains which contain SH (sulfhydryl group)
36
Ionic bond
attraction or repulsion due to charge (+/- attract)
37
Ionic bond strength/weakness
S: bring together over great distances
W: pH dependent
38
Van der Waals interaction
form between 2 atoms that have some charge or polarity
39
hydrophobic interactions
tendency of hydrophobic molecules to be excluded from interactions with water
40
Functional protein structure form during...
tertiary and quaternary structure levels
41
DNA & RNA functions
DNA: storing genetic info
RNA: transmit and express genetic info
42
5 carbon sugar (ribose sugar) + nitrogenous base =
deoxynucleoside
43
deoxynucleoside + phosphate =
deoxynucleotide (monomer of DNA)
44
DNA bases
Purines: adenine (A), guanine (G)
Pyrimidines: thymine (T), cytosine (C)
45
Deoxynucleotides have...
1 to 3 phophates attached to the ribose sugar
1) monophosphate
2) disphosphate
3) triphosphate
46
To get deoxyribonucleotide (monomer) into a deoxyribonucleic acid (polymer) another...
condensation reaction is needed between "P group" & ribose 3' Carbon Hydroxyl group
47
Absence of _____ at _____ of ribose sugar allows _____
O atom, 2' carbon, double helix
48
2 major differences between deoxynucleotides (DNA) & nucleotides (RNA)
Sugar and bases
49
RNA bases
Purines:adenine (A), guanine (G)
Pyrimidines: Uracil (U), cytosine (C)
50
4 subtypes of RNA
- 1) messenger RNA (mRNA) **
- 2) ribosomal RNA (rRNA) **
- 3) transfer RNA (tRNA) **
- 4) microRNA (miRNA)
* * are involved in protein synthesis
51
mRNA
serves as messenger between DNA and ribosomes for protein synthesis
52
rRNA
component of a ribosomes which is essentail for protein synthesis, responsible for reading order and linking amino acids
53
tRNA
brings amino acids to ribosome for proteins synthesis
54
Cystic fibrosis
- caused by mutations or errors in the cystic fibrosis transmembrane conductance regulator (CFTR) gene which results in
- 1) no CFTR protein being mande
- 2) malformed CFTR protein
55
3 functions of lipids
1) energy storage
2) membrane stucture
3) specific biological functions
56
fatty acid
long unbranched chain of hydrocarbons with a carboxyl group at one end.
57
Typical fatty acid size
12-20 carbon atoms per chain
58
Triglycerides
composed of 1 glycerol + fatty acids, linked by ester bonds
59
phospholipid backbone
phosphoglycerate (glycerol + phosphate)
60
phosphoester bond
bond between a phosphorous atom of a phosphate group and an oxygen atom
61
Saturated fatty acids
fatty acid side chains are straight, decrease membrane fluidity
62
unsaturated fatty acids
fatty acid double bonds create kinks, increase membrane fluidity
63
Glycolipids
carbohydate groups attached to lipids forming glycolipids
| function: communication and sensing of events external to cells
64
Steroids
4 ring hydrocarbon skeleton
| most common form is cholesterol
65
functions of cholesterol
imporatnt component of cell membranes, acts as signaling molecule, building block for sex hormones & glucocoticoids
66
Size conversions (MEMORIZE!)
m (1), cm (10^2), mm (10^3), um (10^6), nm (10^9)
67
How many bonds can hydrogen form
1 bond
68
How many bonds can carbon form
4 bonds
69
How many bonds can nitrogen form
3 bonds
70
How many bonds can oxygen form
2 bonds
71
bond energy
amount of energy to break bond with carbon is inversely proportional to weight of atoms
72
Cohesion of water
definition: ability of water molecules to stick to themselves
73
Exocytosis
exiting cell: secrete waste, proteins, neurotransmitters
74
Endocytosis
bring into cell: phagocytosis, pinocytosis
75
Mitochondria function
aerobic respiration (32 ATP), requires oxygen
76
Ribosome type and function
1) free floating in cytosol
2) bound to ER
function: to build polypeptide chains and read mRNA
77
3 organelles in the endomembrane system and function
Endoplasmic reticulum
golgi apparatus
lysosomes & secretory vesicles
primary function: protein synthesis, folding & transport
78
Rough ER
dots = ribosomes
| polypeptide synthesis
79
Smooth ER
no dots = no ribosomes
no role in protein synthesis
produce lipids/steroid, detox drugs
80
Rough ER 4 steps
- 1) Ribosome making protein/polypeptide chain
- 2) binds to receptor
- 3) membrane pore opens
- 4) Protein is finished being built and deposited into lumen of RER
81
9 steps of vesicle-mediated transport
1) cargo selection
2) budding
3) scission
4) uncoating
5) transport
6) tethering
7) docking
8) fusion
9) disassembly
82
Golgi apparatus definition and function
stack of flattened vesicles (cisternae)
| processing and packaging proteins, "post office" of the cell
83
2 networks within the golgi
1) cis-golgi network: closest to nucleus, receives proteins and lipids from ER
2) trans-golgi network: furthest from nucleus, sorts proteins exiting golgi apparatus
84
Coat proteins
1) clatherin - endocytosis
2) COP II - vesicles from ER to Golgi
3) COP I - vesicles from Golgi to ER
85
Endosome
sorting compoartments
86
Early endosomes
Derived from vesicles originated from the plasma membrane
- fuse with vesicles from TGN to create new early endosomes or with preexisitng early endosomes
- drop in pH dissociate the proteins from their receptors
87
when pH of endosomes drops below ____, it is now a _________
6.0, late endosome
88
Lysosome
point of no return
| late endosome matures to a lysosome when pH reaches 5.0
89
____ make up 50% of weight of the plasma membrane
phospholipids
90
Head of a phospholipid is....
made up of a glycerol backbone + phosphate and "head group"
91
Glycolipids
cell-to-cell interactions
92
Sterols
stability
93
2 key models of plasma memrbane
1) Fluid-mosaic model
- lateral mobility
- mosaic proteins
2) lipid raft
- different composition than rest of membrane due to high concentration of cholesterol and glycosphingolipids
94
4 subtypes of integral membrane protein
integral monotopic protein, singlepass protein, multipass protein, multi-subunit protein
95
Peripheral membrane protein
do not penetrate cell membrane, bound to surface of plasma membrane by electrostatic forces
96
Lipid anchored membrane protein
one sided, bonded to lipid layer
97
Functions of membrane proteins
- receptors
- transport
- endocytosis and exocytosis
- authophagy
- enzymes
- electron transport proteins
- anchors
98
membrane proteins are important in _____ of _____ because the plasma membrane is _______
movement, solutes, selectively permeable
99
Signal transduction
external stimulus can result in changes within the cell
100
Simple diffusion definition
unassisted movement of a solute from high to low concentration (down the concentration gradient)
ex. gases, non-polar molecules, small polar molecules
* slow process
101
Facilitated diffusion
move down the concentration gradient towards equilibrium through the usage of transmembrane proteins
102
Channel proteins
- create a hydrophilic channel
| - 2 types: pores and ion channels
103
Ion channels
Movement of ions and water
strengths: move specific ions, very fast
many are gated
104
Porins
within animals cells: mitochondria
| movement of hydrophilic solutes
105
aquaporins
movement of water, highly expressed in kidneys
106
active transport definition
movement of ions and/or molecules across a cell membrain against the concentration gradient
107
Active transport key roles in cell include...
- maintenance of membrane potential
- uptake of essential nutrients
- waste removal
- Maintain non-equilibrium of substances
108
active transport results in a _____ membrane potential (range ____mV to ____mV)
negative, -20, 100
109
Primary active transport
DIRECT use of energy to move molecules across membrane against their concentration gradient
ex. sodium-potassium pump
110
secondary active transport
uses the electrochemical gradient generated elsewhere from active transport as an energy sourse to move molecules against their concentration gradient
INDRECT use of energy
111
two types of secondary active transport
1) symport
| 2) antiport
112
Carb:
| monomer, polymer, bond
monosaccharide
polysaccharide
glycosidic
113
Protein:
| monomer, polymer, bond
amino acids
polypeptides
peptide bond
114
Nucleic acid:
| monomer, polymer, bond
nucleotide
nucleic acid
phosphoester bond
115
Lipids:
| monomer, polymer, bond
Fatty acids, glycerol, phosphate
triglyceride, phospholipids, etc.
ester & phosphoester bond
