BIO Ch. 1 Flashcards
(91 cards)
1
Q
Matter
A
Anything that takes up space and has mass
2
Q
Element
A
A pure substance that has specific physical/chemical properties and can’t be broken down into a simpler substance
3
Q
Atom
A
The smallest unit of matter that still retains the chemical properties of the element
4
Q
Molecule
A
Two or more atoms joined together
5
Q
Intramolecular forces
A
Attractive forces that act on atoms WITHIN a molecule
6
Q
Intermolecular forces
A
Forces that exist BETWEEN molecules and affect physical properties of the substance (boiling point, melting point, density, etc.)
7
Q
Monomers
A
Single molecules that can potentially polymerize
8
Q
Polymers
A
Substances made up of many monomers joined together in chains
9
Q
Organic molecules
A
Molecules made up of carbon atoms that tend to bond with hydrogen, oxygen, nitrogen
10
Q
Carbohydrates
A
Contain C,H, and O atoms
11
Q
Monosaccarides
A
Carbohydrate monomers with empirical formula of (CH2O)n. “n” represents the number of carbons
12
Q
Ribose
A
5-carbon monosaccaride
13
Q
Fructose
A
6-carbon monosaccharide
14
Q
Glucose
A
6-carbon monosaccharide
15
Q
Isomers
A
Same chemical formula, different arrangement of atoms (e.g. glucose and fructose)
16
Q
Disaccharides
A
Two monosaccharides joined together by a glycosidic bond (result of dehydration (condensation) reaction)
17
Q
Dehydration (condensation) reaction
A
A water molecule leaves and a covalent bond forms
18
Q
Hydrolysis reaction
A
A covalent bond is broken by addition of water
19
Q
Sucrose
A
Disaccharide made of glucose + fructose
20
Q
Lactose
A
Disaccharide made of galactose + glucose
21
Q
Maltose
A
Disaccharide made of glucose + glucose
22
Q
Polysaccharides
A
Multiple monosaccharides connected by glycosidic bonds to form long polymers
23
Q
Starch
A
An alpha-1,6 bonded polysaccharide form of energy STORAGE for plants. Linear starch is called amylose; the branched form is amylopectin
24
Q
Amylose
A
Linear starch
25
Amylopectin
Branched starch
26
Glycogen
An alpha-1,4 bonded polysaccharide form of energy STORAGE for humans. (Much more branching than starch).
27
Glucans
The most abundant polysaccharides in the cell walls of fungi
28
Cellulose
A beta bonded polysaccharide that is a STRUCTURAL component in plant cell walls. Linear strands packed rigidly in parallel
29
Chitin
A beta bonded polysaccharide with nitrogen added to each monomer. It is a STRUCTURAL component in fungi cell walls and insect exoskeletons.
30
Alpha vs Beta Polysaccharides
Alpha: OH group points down in ring structure
Beta: OH group points up in ring structure
31
Proteins
Contain C,H, O and N atoms which combine to form amino acids that link together to build polypeptides (or proteins).
32
Proteome
All the proteins expressed by one type of cell under one set of conditions
33
Amino acids (a.a.)
The monomers of proteins. (Structure is carbon bonded to Hydrogen, amino (NH3+), carboxyl (CO2) and R-group (variant). There are 20 different kinds of amino acids, each with a different "R-group"
34
Polypeptides (joining and breaking)
Polymers of amino acids joined by peptide bonds through dehydration (condensation) reactions). Hydrolysis reactions break peptide bonds. Polypeptide becomes an amino acid chain that contains two end terminals on opposite sides.
35
N (amino) terminus
Side of polypeptide that ends with last amino acid's amino group
36
C (carboxyl) terminus
Side of polypeptide that ends with the last amino acid's carboxyl group
37
Primary protein structure
Sequence of amino acids
38
Secondary protein structure
Intermolecular forces between the polypeptide BACKBONE (not R-groups) due to hydrogen bonding between the carbonyl (C=O and amino (NH2) groups. Forms alpha-helices or Beta-pleated sheets
39
Transition state
Unstable conformation between reactant and products
40
Disulfide bonds
A tertiary protein structure created by covalent bonding between the R-groups of 2 CYSTEINE amino acids
41
Quaternary protein structure
Multiple polypeptide chains come together to form one protein
42
Protein classification based on STRUCTURE
Fibrous, globular or intermediate
43
Tertiary protein structure
3-D structure due to interactions BETWEEN R-GROUPS (ionic bonding, H-bonding, dipole-dipole interactions, london dispersion (van der Waal forces). Can create hydrophobic or hydrophilic spaces based on the R-groups. Disulfide bonds are created by covalent bonding between the R-groups of two cysteine amino acids
44
Protein denaturation
Loss of protein function and higher order structures. Primary structure remains unaffected.
45
Proteins denature as a result of...
High or low temperatures, pH changes, and salt concentrations.
46
Protein functions
Storage, hormones, receptors, motion, structure, immunity, enzymes
47
Protein classification based on COMPOSITION
Simple (amino acids only) or conjugated (amino acids + other components)
48
Enzymes
Act as biological catalysts by binding to substrates (reactants) and converting them into products. Most enzymes are proteins
49
Catalysts
INCREASE REACTION RATES by lowering the ACTIVATION ENERGY of a reaction. The TRANSITION STATE is the unstable conformation between reactants and products. Catalysts reduce the energy of the transition state. Catalysts do not shift a chemical reaction or affect spontaneity. (Do not change the net amount of energy a reaction might absorb or release)
50
Hydrogen Bonds
Can only occur between H and F,O or N.
51
Active site
Enzymes bind substrates at active site which is specific for the substrate that it acts upon. (Active site is located on the enzyme NOT the substrate)
52
Specificity constant
Measures how efficient an enzyme is at binding to the substrate and converting it to a product
53
Induced fit theory
Describes how the active site molds itself and changes shape to fit the substrate when it binds. The "lock and key" model is an outdated theory of how substrates bind
54
Ribozyme
An RNA molecule that can act as an enzyme (a non-protein enzyme)
55
Cofactor
A non-protein molecule that helps enzymes perform reactions. A coenzyme is an organic cofactor (i.e. vitamins). Inorganic cofactors are usually metal ions
56
Coenzyme
An ORGANIC cofactor (i.e. vitamins). Inorganic cofactors are usually metal ions
57
Holoenzyme
Enzymes that are bound to their cofactors
58
Apoenzyme
Enzymes that are NOT bound to their cofactors
59
Prosthetic groups
Cofactors that are tightly or covalently bonded to their enzymes
60
Protein enzyme denaturation
Protein enzymes are susceptible to denaturation. They require optimal temperatures and pH for function.
61
Competitive inhibition
Competitive inhibitor competes directly with the substrate for active site binding. The rate of enzyme action can be increased by adding more substrate.
62
Noncompetitive inhibition
Noncompetitive inhibitor binds to an allosteric site (a location on an enzyme that is different from the active site) that modifies the active site. In noncompetitive inhibition, the rate of enzyme action CANNOT be increased by adding more substrate.
63
Enzyme Kinetics Plot
Used to visualize how inhibitors affect enzymes. The x-axis represents substrate concentration [X] while the y-axis represents reaction rate of velocity (V)
64
Vmax (Enzyme Kinetics Plot)
The maximum reaction velocity
65
Michaelis Constants (Km) (Enzyme Kinetics Plot)
The substrate concentration [X] at which the velocity (V) is 50% of the maximum reaction velocity (Vmax).
(A small Km implies we only need a little bit of substrate because ability/function is high)
66
Saturation (Enzyme Kinetics Plot)
Occurs when all active site are occupied, so the rate of reaction does not increase anymore despite increasing substrate concentration (causes graph plateus)
67
Enzyme Kinetics Plot Competitive Inhibition
Km increases, while Vmax stays the same.
(As we add more substrate, the probability that a substrate will occupy the active site over a competitive inhibitor increases. Therefore, the substrate concentration [X] required to reach 50% of Vmax increases, meaning Km increases; however the Vmax is unaffected).
68
Enzyme Kinetics Plot Noncompetitive Inhibition
Km stays the same, while Vmax decreases.
(A noncompetitive inhibitor binds to the allosteric site of enzymes, and increasing the substrate concentration [X] will only increase the velocity (V) a certain amount because we CANNOT outcompete allosteric inhibitors. Therefore, Km remains the same because the Vmax decreases, which proportionally decreases the substrate concentration [X] required to reach 50% of the new Vmax).
69
Phosphatase
Enzyme cleaves a phosphate group off of a substrate molecule
70
Phosphorylase
Enzyme adds a phosphate group to a substrate molecule using inorganic phosphate to break bonds within a substrate
71
Kinase
Transfers phosphate group from an ATP molecule to a substrate molecule. Kinases do NOT break bonds in order to add a phosphate group
72
Lipids
Contain C, H, and O atoms. Very long hydrocarbon tails that make them very hydrophobic.
73
Triacyglycerol (triglyceride)
A lipid molecule with a glycerol backbone (3C + 3OH groups) and t3 fatty acids (long hydrocarbon tails). Glycerol and the 3 fatty acids are connected by ester linkages
74
Saturated Fatty Acids
No double bonds and as a result pack tightly (solid at room temperature)
75
Unsaturated fatty acids
Have double bonds
76
Monounsaturated fatty acids
ONE double bond
77
Polyunsaturated fatty acids
TWO or MORE double bonds
78
Cis-unsaturated fatty acids
Have KINKS that cause the hydrocarbon tails to bend. Do NOT pack tightly
79
Trans-unsaturated fatty acids
Straighter hydrocarbon tails. Pack TIGHTLY
80
Phospholipids
Lipid molecules that have a glycerol backbone, one phosphate group and 2 fatty acid tails. Amphipathic because the phosphate group is polar while fatty acids are non-polar. Spontaneously assemble to form lipid bilayers
81
Cholesterol
Amphipathic lipid molecule that is a component of the cell membranes. The most common precursor to steroid hormones (lipids have four hydrocarbon rings). Cholesterol is also the starting material for vitamin D and bile acids
82
Factors that influence membrane fluidity
1. Temperature: increased temperatures increase fluidity while decreases temperatures decrease it
2. Cholesterol: holds membranes together at high temperatures and keeps membranes fluid at low temperatures
3. Degrees of unsaturation: saturated fatty acids pack more tightly than unsaturated fatty acids, which have double bonds that may introduce kinks
83
Lipoproteins
Allow transport of lipid molecules in the bloodstream due to an outercoat of phospholipids, cholesterol, and proteins
84
Low-density lipoproteins (LDLs)
"Bad Cholesterol" Low protein density and work to deliver cholesterol to peripheral tissues. Can cause vessel blockage and heart disease
85
High-density lipoproteins (HDLs)
"Good Cholesterol" High protein density and take cholesterol away from peripheral tissues and deliver to the liver to make bile. Reduces blood lipid levels.
86
Waxes
Simple lipids with long fatty acid chains connected to monohydroxy alcohols (contain a single hydroxyl group) through ester linkages. Used mainly as hydrophobic protective coatings
87
Carotenoids
Lipid derivatives containing long carbon chains with conjugated double bonds and six-membered rings at each end. Function mainly as pigments
88
Sphingolipids
Have backbone with aliphatic (non-aromatic) amino acids and serve important functions in the plasma membranes of cells.
89
Nucleic acids
Contain C, H, O, N and P atoms. Contain nucleotide monomers that build into DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) polymers
90
Nucleosides
5-carbon sugar and a nitrogenous base.
91
Nucleotides
5 carbon sugar, a nitrogenous base, AND a phosphate group
