BIO 160 Exam 2 Flashcards
1
Q
Adhesion
A
Attraction between different substances (cell wall and H2O)
2
Q
Transpiration
A
Evaporation of H2O from plants. Creates a tension that pulls water up the plant
3
Q
Surface tension
A
A measure of how hard it is to break the surface of a liquid
4
Q
Kinetic energy
A
Energy of motion
5
Q
Thermal energy
A
The kinetic energy associated with random motion of atoms or molecules
6
Q
Temperature
A
A measure of energy that represents the average kinetic energy of the molecules in a body of matter
7
Q
Heat
A
Thermal energy in transfer
8
Q
Calorie
A
The amount of heat required to raise the temperature of 1g of water by 1 degree Celsius
9
Q
Kilocalorie
A
Food calories. 1000 cal = 1 kilocalorie
10
Q
Joule
A
1 cal = 4.184 J
11
Q
Specific heat
A
The amount of heat that must be added or lost for 1 g of that substance to change its temp by 1 degree Celcius
12
Q
Heat of vaporization
A
The heat of a liquid that must be absorbed for 1 g to be converted to a gas
13
Q
Evaporative cooling
A
As a liquid evaporates its remaining surface cools. This helps stabilize temperatures in organisms and bodies of water
14
Q
When is water the most sense?
A
At 4 degrees Celcius
15
Q
Solution
A
Is a liquid that is a completely homogeneous mixture of substances
16
Q
Solvent
A
The dissolving agent of a solution
17
Q
Solute
A
The substance that is dissolved
18
Q
Aqueous solution
A
Water is the solvent
19
Q
Why is water a versatile solvent?
A
Because water is polar
20
Q
Hydration shell
A
When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules
21
Q
Hydrophilic
A
Water loving
22
Q
Hydrophobic
A
Water hating
23
Q
Molarity
A
The number of moles of solute per liter of solution
24
Q
Acid
A
Any substance that increases H+ concentration of a solution
25
Base
Any substance that reduces the H+ concentration of a solution
26
Buffers
Substances that minimize changes in concentrations of H+ and OH - in a solution
27
Bicarbonate buffering
The main way humans control pH in our blood
28
What is the pH of blood?
7.35-7.45
29
Ocean acidification
Carbon dioxide is dissolved in sea water and forms carbonic acid
30
Hydrocarbons
Organic molecules consisting of only carbon and hydrogen
31
Isomers
Compounds with the same molecular formula but with different structures and properties
32
Structural isomers
Different covalent arrangements of their atoms
33
Enantiomers
Isomers that are mirror images of each other
34
4 classes of large biological molecules
Carbohydrates
Lipids
Proteins
Nucleic acids
35
Macromolecules
Polymers built from monomers
36
Polymer
A long molecules consisting of many similar building blocks (monomers)
37
Monomers
Repeating units that serve as building blocks
38
Enzyme
Specialized macromolecules that speed up chemical reactions
39
Dehydration reaction
When two monomers bond together through the loss of a water molecules.
Forms new bond for longer polymer
40
How are polymers disassembled?
By monomers through hydrolysis
41
Hydrolysis reaction
Adds water. Breaks the bond.
42
Carbohydrates
Fuel, building material, includes sugars and polymers of sugars
43
Polysaccharides
Polymers composed of many sugar building blocks
44
Monosaccharides
Simplest sugar.
45
What is the most common monosaccharide?
Glucose (C6H12O6)
46
Disaccharide
Formed when a dehydration reaction joins two monosaccharides
47
What is the covalent bond called when a disaccharide forms?
Glycosidic linkage
48
Example of polysaccharide
Starch.
Consists entirely of glucose monomers.
49
What is the simplest form of starch?
Amylose
50
How do plants store starch?
As granules within chloroplasts and other plastids
51
T/F starch is straight and unbranched
False. Starch is largely helical
52
Lipids
Do not include true polymers.
They mix poorly with water because they are non polar because of hydrocarbons
53
Fats
Constructed of glycerol and fatty acids
54
Glycerol
3-carbon alcohol with a hydroxyl group attached to each carbon
55
Fatty acid
Consists of a carboxyl group attached to a long carbon chain
56
Saturated fatty acids
No double bonds. Usually solid.
57
Unsaturated fatty acids
One or more double bonds usually liquid.
58
Cohesion
Hydrogen bonds hold H2O molecules together
59
Unifying feature of lipids
They mix poorly with water if at all. Hydrophobic because they consist mostly of hydrocarbons which form nonpolar covalent bonds
60
Phospholipids
Two fatty acids and a phosphate group are attached to glycerol. Fatty acid tails are hydrophobic. Phosphate group and its attachments form a hydrophilic head
61
Steroids
A lipid characterized by a carbon skeleton consisting of four fused rings
62
Cholesterol
A type of steroid. It's a component in animal cell membranes and a precursor for which other steroids are synthesized
63
Name all types of proteins
```
Enzymatic
Defensive
Storage
Transport
Hormonal
Receptor
Contractile and Motor
Structural
```
64
What are amino acids
Organic molecules with amino and carboxyl groups.
There are 20 standard amino acids
65
How do amino acids differ
Differ in their properties because of different side chains called R Groups
66
What is a polypeptide?
A polymer of amino acids
67
Are polypeptides unique?
Yes. Each polypeptide has a unique linear sequence of amino acids with a carboxyl end and an amino end
68
What are the four levels of protein structure?
Primary
Secondary
Tertiary
Quaternary
69
What reinforces a proteins structure?
Disulfide bridges which are strong covalent bonds
70
Tertiary structure results from..
Interactions between R grounds. These interactions include hydrogen bonds, ionic bonds, hydrophobic interactions, and van der waals interactions
71
Quaternary structure results from...
When two or more polypeptide chains form one macromolecule
72
Sickle cell disease results from..
A single amino acid substitution in the protein hemoglobin
73
What determines protein structure?
Alternations in pH, salt concentrations, and temperature
74
Denaturation
Loss of proteins native structure
75
What is the function nucleic acids?
They store, transmit, and help express hereditary information
76
What is a gene
The amino acid sequence of a polypeptide is programmed by a unit of inheritance
77
Two types of nucleic acids
Deoxyribonucleic acid (DNA)
ribonucleic acid (RNA)
78
T/F. DNA provides directions for its own replication
True
79
How is DNA involved in protein synthesis?
DNA directs synthesis of messenger RNA and mRNA controls protein synthesis. This is called gene expression
80
What are adjacent nucleotides joined by
Phosphodiester linkage. This creates a backbone of sugar phosphate units
81
How do backbones run
They run opposite. 5 to 3. 3 to 5.
82
T/F. RNA is double stranded.
False. RNA is single stranded.
83
What are the nucleotides of DNA
Cytosine, Guanine
| Adenine, thymine
84
What nucleotide is replaced in RNA?
Thymine is replaced by uracil.
85
What is the most abundant lipid in the plasma membrane?
Phospholipid
86
Definition of amphipathic
Containing both hydrophobic and hydrophilic regions
87
Are phospholipids amphipathic molecules?
Yes.
88
T/F. Proteins are randomly distributed in the plasma membrane.
False.
89
What is cholesterols effect on membranes?
At warm temps, restrains movement of phospholipids
At cool temps, it maintains fluidity by preventing tight packing
90
Carrier proteins
Bind to molecules and change shape to shuttle them across the membranes
91
Transport proteins
Allow passage of hydrophilic substances across the membrane
92
Channel proteins
Have a hydrophilic channel that certain molecules or ions can use as a tunnel
93
Aquaporins
Channel proteins that facilitate the passage of water
94
What is passive transport
Diffusion of a substance across a membrane with no energy required
95
Diffusion
Is the tendency for molecules to spread out evenly into the available space
96
Define concentration gradient
The region along which the density of a chemical substance increases or decreases
97
Osmosis
The diffusion of water scores a selectively permeable membrane
98
What is tonicity?
The ability of surrounding solution to cause a cell to gain lose water
99
Isotonic solution
Solute concentration is the same as that inside the cell. No net water movement across plasma membrane
100
Hypertonic solution
Solute concentration is greater than that inside the cell. Cell loses water
101
Hypotonic solution
Solute concentration is less than that inside the cell. Cell gains water.
102
Active transport
Uses energy to move solute against their gradients. Performed by specific proteins embedded in the membranes. Allows cells to maintain concentration gradients that differ from their surroundings.
103
Proton pump
The main electrogenic pump of plants fungi and bacteria
104
Does bulk transport use energy?
Yes.
105
T/f. Large molecules such as polysaccharides and proteins across the membrane in bulk via vesicles
True.
106
What are the three types of endocytosis bulk transport?
Phagocytosis
Pinocytosis
Receptor-mediated
