Chapter 1-3 (BIOL 131) Flashcards
BIOL 131
1
Q
biology
A
study of living things, very broad
2
Q
living things exhibit
A
-reproduce, respond to the environment, grow, evolve, metabolism
-only some characteristics? complex but not living
- virus, no metabolism, living? generally no but in cells yes
3
Q
3 domains classifying life
A
bacteria, eukarya, archaea
4
Q
phylogenic tree
A
displays evolutionary relationships
5
Q
naming
A
DKPCOFGS
6
Q
hierarchy
A
biosphere-ecosystem-community-population-organism-organ-tissue-cells-organelles-molec-atoms (*smallest)
7
Q
2 main science approaches
A
- observational/discovery (inductive reasoning, qualitative, little ideas to big idea)
- hypothesis based (deductive reasoning, quantitative, testing hypotheses, big idea to little ideas)
8
Q
scientific method
A
*consider scale
1- observe 2-question 3-hypothesis 4- perform experiment 5- analyze data 6- conclusion
9
Q
hypothesis must be
A
falsifiable but cannot be proven
10
Q
beware pseudoscience
A
more observations- new conclusions (science changes to fit available data)
11
Q
most important matters related to life
A
- nucleic acids
-proteins - lipids
- carbohydrates
12
Q
living organisms are composed of
A
25 key elements (CHNOPS)
13
Q
elements are composed of – and combine to form –
A
atoms, molecules
14
Q
elements
A
- 92 different elements occur naturally on earth
- 15 artificial elements
- pure substance that cannot be broken down simpler (chem/physically)
15
Q
matter
A
anything that occupies space and has mass
16
Q
atoms
A
smallest unit, retains chem/physical properties of element
- consist of nucleus surrounded by e-
17
Q
electrons
A
may occupy more than 99.99% of space
- surround the nucleus in orbitals
- move very fast (approach speed of light)
18
Q
nucleus
A
more than 99.99% of mass, matter is mostly empty space
- contains protons (=atomic #) and neutrons
19
Q
orbital
A
region around nucleus where e- spends most time
- most contain 2e- for balance
- occur in layers
20
Q
e- exist
A
in lowest energy shell available, closest to nucleus
- Bohr diagrams show this
21
Q
chemical bonds
A
- unstable config
- share e-
- join orbitals w other atoms to reach stable config.
22
Q
important bonds for chemical systems (order most stability to least)
A
- covalent
- ionic
- hydrogen
- van der waals forces
23
Q
ionic bonds
A
- atoms lose or gain ve-
- form pos or neg ion
- diff in charge causes attraction
- metals lose e-, nonmetals gain e-
24
Q
covalent bond
A
- e- in shared orbitals
- shared to fill valence
- total possible bonds = # empty spots in valence shell
25
electronegativity (charges!)
- atoms attraction for an e-
- unequal e- sharing results in polarity
polar covalent: partia charges
ionic: full charges
nonpolar: no charge
26
polar molecule
- associate w eachother
- exclude non polar
-hydrophilic
27
non polar molecule
- do not associate w polar
- hydrophobic (ex. oil)
28
polar or non polar???
depends on bond type and molec shape (ex. linear cancels charges)
29
hydrogen bonds
- unequal e- sharing
- hydrogen atoms
- weak bonds
- makes ice less dense than liquid water, floats bc lattice structure
30
role of HB
-3D stability of large molecules (protein mol into helical)
- weak compares to ionic/cov.
- weak bonds breaking @45 and gone @100
31
Van Der Waals interactions
- temporarily attraction between atoms, create by changing position of e-
- weak attraction, short distances
- e- accumulate in one part, creates polarity (ex. geckos)
- graphite (layer by layer)
32
waters importance
- supports all life
- 75% of earth
- life evolved in water
- cells are mostly water
33
emergent properties
1) water exhibits cohesion
2) moderates temp
3) ice floats on water
4) water is the solvent of life
34
cohesion vs adhesion
ex) insect walking on water
cohesion: keep molec close together
adhesion: polar charges attract other surfaces (moves water from roots to plants)
35
heat =
total kinetic energy of matter
- is a result of motion of molec
- heat does not equal temp
36
units (cal, kilo cal, joule)
cal: heat required to raise 1g by 1*C)
kilocalories: 1000cal
joule: 0.239cal (1cal=4.185J)
37
specific heat
amount heat required to raise 1g substance 1*C
- aluminum cookware has lower specific heat than water
38
closer to water
stable, moderated temps (not extremes)
39
evaporative cooling
water has a high heat of evaporation
- evap 1g water requires around 580 cal
40
ice floats: HB
liquid- HB break and reform
ice- HB are stable
41
water is the solvent of life
solution: a homogenous mixture
solvent: dissolving agent
solute: is dissolved
- when water is the solvent, results in aq solution
42
molec mass
sum of all masses of atoms in a molec
43
acid vs base
acid- H+ source
base- H+ remover
44
strong vs weak
strong: completely ionizes, strong electrolyte, ionic/polar (acids- HCLO4, H2SO4, bases- NaOH, LiOH)
weak: partially ionizes, weak electrolytes, some covalent bonds
45
acid properties
sour, conduct electricity, corrosive, some react strong w metal
46
base properties
slippery, taste bitter, corrosive, can conduct electricity (ex. alkaline battery), do not react w metals
47
acid- base reactions
is called neutralization
- result is not as acidic or basic as starting solutions
48
pH scale
- based on proton (hydrogen) concentration
pH<7 acidic
pH>7 basic
pH=7 neutral
49
buffers
compound that stabilizes the pH of a solution by dynamically resisting change ex) body fluids keep internal environment stable in organisms.
50
the backbone of life
carbon!
- 4ve
-abundant, lightest in its group, can form 4 bonds
(not silicon! twice as heavy, less flexible, non chiral)
51
1800s
synthesizing simple molec compounds in the lab, but complex compounds seemed impossible
--> "vitalism"
52
Louis Pasteur
convinced scientists that living organisms to not arise spontaneously
- HOWEVER- others proposed life originated after a long period of nothing
53
the 1st organic molecules
miller and Urey
- tried to replicate early earth conditions
- produced 21 amino acids
progression from "vitalism" to mechanism
- demonstrated 'chemical evolution"
(rules of chem apply to ALL molec)
54
molec diversity arising from carbon skeletons
length, branching, double bond position, presence of rings
55
hydrocarbons
- only contain H and C, can be huge, hydrophobic, store large amounts of energy
56
isomer
same chem formula (# atoms), different structure
57
structural isomers
diff structure
58
cis-trans isomers
cis isomer: Xs on same side
trans isomer: Xs on opp sides, diagonal
59
enantiomers
flipped, chiral, mirror images (left vs right hand) (recall pharmacy examples, ibuprofen and albuterol)
60
-OH
hydroxyl
- alcohols (names usually end in -ol)
- polar bc of oxygen
- forms hydrogen bonds, dissolves org. compounds
61
-C=O
carbonyl
- ketone (if carbonyl is within carbon skeleton) or aldehyde (if at end of skeleton)
- are found in sugars (ketoses, aldoses)
62
-COOH
carboxyl
- carboxylic acid or organic acid
- acts as acid
- carboxylate ion 1- found in cells
63
-N-H2
amino
- acts as a base, picks up H+
- found in cells with 1+ charge
64
-SH
sulfhydryl
- thiols
- 2 sulfhydryl groups can react and form cov. bond, "cross-linking" (stabilizes protein structure)
- cysteines cross-linking causes hair type
65
-P-O3=O
phosphate
- organic phosphates
- neg charge to the molec (2- when at end, 1- when internal)
- can react w water, release energy
66
-CH3
methyl
- methylated compounds
- affects expression of genes
- arrangement in sex hormones affects shape + function
67
ATP
metabolic currency
ATP--> inorganic phosphate+ ADP+ energy
68
macromolecules
polymers built from monomers
69
dehydration rxn
removes a water mol, forms a new bond
70
hydrolysis
breaking down a polymer, adds water and breaks a bond
71
order is everything
simple variation in sequence of monomers can hugely impact final form or function
72
carbohydrates
- polar molec that like water
general form: Cn(H2O)n
- source of stored energy, carbon skeleton
- small to very large
73
monomers
monosaccharide, single simple sugars
74
disaccharides
two simple sugars, two monosaccharides linked by condensation, *glycosidic linkages)
75
oligosaccharides
several, 3-20 simple sugars
- many have additional functional groups (ABO blood types)
76
polymers
polysaccharides, hundreds or thousands of simple sugars
- links by condensation
functions- storage of energy or structure
(starch stores sugar in plants, glycogen stores sugar in animals, cellulose- structural sugar in plants)
77
monosaccharide examples
1- glucose
2- other hexoses (6C isomers)
3- pentoses (5C sugars, ribose and deoxyribose)
78
what sugars do we use
- sucrose
- glucose + fructose (hydrolyze starch into components, cheaper and easier to mix)
79
macromolecular structure (3 types)
- linear (cellulose)
- branchers (starch
- highly branched (glycogen)
80
carbohydrates w additional functional groups
- intermediate in cellular reactions ex) fructose 1-6 biphosphate
81
chemically modified carbohydrates
- an important component of extracellular matrix
ex) amino sugars: glucosamine, galactosamine
chitin: external skeleton of insects and fungal cell walls
82
lipids
fats and oils
- water-insoluble, non-polar -hormones
functions: energy storage, cell membrane, waterproofing, insulation, capture light energy
types: triglycerides, phospholipids, lipids w out glycerol fatty acid structure (4 subs)
83
monomer of protein is
amino acids (link through dehydration)
84
triglycerides
fats and oils, energy storage
- 1 glycerol and 3 fatty acids
- linked by condensation --> *Ester linkages*
85
saturated fats (lard) vs unsaturated fats (plant oils)
saturated: no double bonds
unsaturated: double bonds, bend chains
86
phospholipids
major component cell membranes
- 1 glycerol + 2 fatty acids + 1 phosphate
87
amphipathic
two opposing chemical properties, ex. phospholipid bilayer
88
other lipids WITHOUT a glycerol fatty acid structure
1) carotenoids: light-absorbing pigments
2) steroids: 4 fused C rings + functional grps
3) anabolic steroids: synthetic variants
4) some vitamins: small molec not synthesized by humans
5) waxes: 1 saturated fatty acid chain + 1 saturated alcohol chain
89
Proteins: 8 functional types
enzymes, storage, regulation, movement, defence, transportation, receptor, structure
90
enzymatic proteins
- selectively accelerates chem rxns
- digestive enzymes catalyze hydrolysis
91
storage proteins
- store amino acids
- casein- baby mammals
- plants have in seeds
- ovalbumin, egg white, develops embryo
92
regulation: hormonal proteins
- coordinates organisms' activities
- insulin (regulates blood sugar concentration)
93
movement: contractile and motor proteins
- motor proteins- responsible for cilia and flagella
- actin and myosin- contraction of muscles
94
defensive proteins
- protect against disease
- antibodies inactive and destroy viruses+bacteria
95
transport proteins
- hemoglobin- transports oxygen from lungs to body
- some proteins transport molec across cell membrane
96
receptor proteins
- response of cell to chemical stimuli
- receptors built into membrane of nerve cell detect others released by other nerve cells
97
structural proteins
- support
- keratin (hair, horn, feathers), insects' silk fibres (for webs), collagen + elastin (for animal connective tissues)
98
protein structure
-Monomers are amino acids
1- amino acid
2- carboxyl group
3- side chain (R group)
4- alpha carbon (centre)
99
20 amino acids of life
- nonpolar side chains; hydrophobic
- polar side chains; hydrophilic
- electrically charged side chain; hydrophilic
- acidic or basic
100
making a polypeptide
dehydration- new peptide bond forms
101
Structures amino acids
Primary:
Secondary: alpha helix, HB, beta pleated sheet
Tertiary: polypeptide, ionic bond, interactions
Quaternary: protein (4 identical polypeptides)
102
denaturation
- temp, pH, polar and nonpolar substances can denature proteins
- secondary and tertiary structure destroyed, biologically inactive
103
chaperone proteins
aka chaperonin
- help prevent inappropriate interactions (ie. binding to wrong substance)
104
what is a nucleic acid
- information carrying biopolymer
- built from nucleotides bonded in precise order
105
components of nucleic acid
1) nitrogenous base : pyrimidines (CT or U) and purines (AG)
2) 5C sugar: ribose or deoxyribose
3) phosphate group
106
nucleotide
nitrogenous base + 5C sugar + phosphate group
107
neucleic acids as polymers
- sugar-phosphate-sugar backbones
- forms phosphodiester linkages
- linked by condensation
- bases stick out
108
complementary base pairing
specific hydrogen bonds: A-T (or A-U in RNA) ( two bonds), G-C (three bonds)
- larger purine w smaller pyrimidine
109
DNA
deoxyribonucleic acid
-deoxyribose sugar, ATGC, two strands * antiparallel
- double-stranded double helix
- uniform structure but HUGE diversity
110
RNA
ribonucleic acid
- ribose sugar, AUGC, single-stranded
secondary: 3D shape of some RNA due to self base pairing
111
central dogma of molec biology
1) DNA can replicate
2) DNA can transmit information
DNA-(transcription)->RNA-(translation)->polypeptide
112
replication and transcription
replication: involves entire molecule (genome)
transcription: involves only small sections (genes)
113
DNA shows evolutionary relationships
closely related species have more similar sequences
114
other nucleotides important roles
ATP - energy transducer
GTP - energy source
cAMP - essential to hormone action
