Biology Midterm: Lectures 1-8 and 27 Flashcards
1
Q
What is biology the study of
A
life
2
Q
characteristics of life (7)
A
- reproduction
- ability to metabolize
- growth and development
- homeostasis
- sense + respond to stimulus
- has order/organization
- adaptation
3
Q
reproduction
A
the ability to generate offspring with new combinations of (parent) DNA
4
Q
ability to metabolize (2 types)
A
- catabolism: break down molecules to yield energy
- anabolism: building up of molecules by using energy
5
Q
growth and development
A
- growth: size
- development: maturation
6
Q
homeostasis
A
the ability to maintain a controlled internal environment
7
Q
sense + respond to stimulus (2 types)
A
- immediate: fight or flight, phototropism
- overtime: evolutionary adaptations that do not just occur in 1 individual
8
Q
has order/organization
A
made up of at least one cell that has chemical structure and cellular processes
9
Q
adaptation
A
changes that occur over time due to natural selection and mutation
10
Q
are viruses living?
A
no, because they require a host to reproduce
11
Q
Classification of Living Organisms (9)
A
- domain (most inclusive and least genetically identical)
- kingdom
- phylum
- class
- order
- family
- genus
- species
- sub species/strain (least inclusive and most genetically identical)
12
Q
How were domains discovered and how many are there?
A
- discovered by woese and fox
- sequenced 165 rRNA genes and found 3 different types
- 3 domains of life
13
Q
What are the 3 domains and their characteristics?
A
-Archaea: prokaryotes single celled extremophiles no nucleus -Bacteria: prokaryotes -Eukarya eukaryotes have a nucleus
14
Q
What organisms are classified as Archaea?
A
- methanogens (organisms that produce methane)
- extreme halophiles (salt loving)
- extreme thermophiles
15
Q
What organisms are classified as bacteria?
A
- gram positive (thick cell walls of peptidoglycan)
- gram negative/proteobacteria (thin cell walls of peptidoglycan)
- cyanobacteria (photosynthesis bacteria)
16
Q
What organisms are classified as eukarya
A
- protista
- fungi
- plantae
- anamalia
17
Q
what is the organism naming system called
A
binomial nomenclature
18
Q
what are the 5 unifying themes of life
A
- organization
- information
- energy and matter
- interactions
- evolution
19
Q
What is organization
A
heirarchy used to organize the study of life
20
Q
what is the order of the heirarchy of life
A
- biosphere
- ecosystem
- community
- population
- organism
- organs
- tissues
- cells
- organelles
- molecules
21
Q
biosphere
A
all life on eart and all of the places where life exists
22
Q
ecosystem
A
all the living things in a particular area, along with all of the nonliving components that life interacts with
23
Q
community
A
the array of organisms that live in an ecosystem
24
Q
population
A
all of the individuals within a species that live in a certain area
25
organism
individual living thing
26
organs
a bodypart made up of multiple tissues, with a specific function
27
tissues
a group of cells that works together to perform a function
28
cells
lifes fundamental unit, the smallest unit of organization that can perform all activities required for life
29
organelles
functional components of cells
30
molecules
a chemical structure consisting of two or more atoms
31
reductionalism
reduces complex systems to simpler components that are more manageable to study
32
emergent properties
new properties emerge at each level that are absent from the one before because complexity increases at higher levels of organizations
33
systems biology
exploring biological systems by analyzing interactions among its parts
34
how do structure and function corralate
you can analyze a structure to find clues about how it's function works
35
cell theory
all living organisms are made up of cells-and the actions of organisms are based on the activities of cells
36
what are the differences between eukaryotic cells and prokaryotes
```
EUKS
-membrane bound organelles
-has a nucleus
PROKS
-lack a nucleus
-no membrane bound organelles
-generally smaller than euks
```
37
where is DNA contained
chromosomes
38
what does DNA contain
genes
39
what are genes
units of inheritance, code the info necessary to build all molecules synthesized in a cell (identity and function)
40
structure of DNA
2 chains arranged in a double helix
41
what are nucleotides
they make up the strands of the double helix
chemical building blocks A,T,C,G
specific sequences of nucleotides encode info in genes (many times it is making protein)
42
producers
photosynthetic organisms that consumers feed on
43
consumers
organisms that feed on other organisms, or their remains
44
what happens when an organism uses chemical energy to do work
some of that energy is lost to the surroundings, in the form of heat
45
how does energy flow through an ecosystem
- in 1 direction
| - usually enters as light and exits as heat
46
how are chemicals recycled in an ecosystem
when chemicals that the plant absorbs have passed through the host's body, the plants re-uptake the chemical again
47
why is feedback regulation important
- interactions between components that make up organisms are crucial to smooth operation
- the output or product of a process is what regulates the process
48
negative feedback loop
the response reduces the initial stimulus
49
positive feedback loop
the response increases the initial stimulus
50
which feedback loop is most common
negative feedback loop
51
3 types of organism interactions
- mutually beneficial
- one species benefits, the other doesn't
- both are harmed
52
relationship between organisms and their environment
organisms help their environments and the environment helps the organisms
53
climate change
a directional change to the global climate that lasts for 3 decades or more
54
evolution
a process of biological change in which species accumulate differences from their ancestors as they adapt to different environments over time
55
the order of naming organisms
1. genus (which the species belongs to)
| 2. unique to the species within the genus
56
what are the 3 domains of life
bacteria
archaea
eukarya
57
domain bacteria
most diverse and widespread prokaryotes
58
domain archaea
live in the earth's most extreme environments (prokaryotes)
59
kingdoms in domain eukarya
- plantae
- fungi
- animalia
- protists
60
kingdom plantae
multicellular eukaryotes that carry out photosynthesis (usually live on land)
61
kingdom fungi
characterized by the nutritional mode, which absorbs nutrients from outside of their bodies
62
kingdom animalia
multicellular eukaryotes that ingest other organisms
63
protists
mostly unicellular eukaryotes and simpler, multicellular relatives
64
what is used to distinguish most of the kingdoms in domain eukarya
nutrition
65
what are the 2 main points in Charles darwin's "On the Origin of Species by Means of Natural Selection"
- species adapt to different environments over time, and accumulate differences from their ancestors (descent with modification)
- natural selection is a primary cause of descent with modification
66
what are darwin's 3 observations of nature
- individuals in a population vary in their traits, many of which seem to be heritable
- a population can produce far more offspring than can survive to produce offspring of their own (more individuals than the environment can support=competition)
- species are generally suited to their environments (adapted to circumstances)
67
what individuals are more likely to survive and reproduce
individuals with inherited traits that are better suited to the local environment, opposed to those who are less well-suited
68
corralation between time and suitable traits
over generations, a higher and higher proportion of individuals in a population will have the advantageous trait
69
darwins proposal of descendant species
-one population of organisms became fragmented into several populations
-b/c they were isolated in different environments
-1 species radiated into multiple species and adapted to the different environments
(galapagos finches)
70
genomics
large scale analysis of the DNA sequences of a species
71
bioinformatics
using computational tools to deal with huge volumes of sequences data
72
compound
made of atoms, joined by bonds
73
what does number of protons determine
determines and atoms identity
74
what does electron distribution determine
ability to form bonds
75
what does a compound's properties depend on
its atoms and how they are bonded together
76
matter
- organisms are composed of it
- anything that takes up space and has mass
- matter is made up of elements
- consists of chemical elements in pure form and in compounds
77
element
a substance that cannot be broken down to other substances by chemical reactions
78
how many elements occur in nature
92
79
compound
a substance consisting of 2 or more different elements combined in a fixed ratio
80
what percentage of the 92 naturally occuring elements are essential
20-25%
81
essential elements
organisms need these to live and to reproduce
82
what are the top 4 essential elements and the % of living matter that they make up
```
oxygen
carbon
hydrogen
-nitrogen
96%
```
83
what are the top 4 trace elements and the % of living matter that they make up
```
calcium
phosphorus
potassium
sulfur
4%
```
84
Atom
smallest unit of matter that still retains the properties of an element
85
subatomic particles
what atoms are composed of...
- protons (+)
- electrons (-)
- neutrons
86
what 2 subatomic particles are almost identical in mass
protons and neutrons (about 1 dalton)
87
characteristics of the atomic nucleus
- protons and neutrons are tightly packed
- electons are moving rapidly
- electrons form a "cloud" of negative charge
- the attraction between the opposite charges keep the electrons near the nucleus
88
what is a Dalton
named after John Dalton who helped develop the atomic theory, and is used to measure atoms/subatomic particles (amu)
89
atomic number
the number of protons unique to that element (bottom)
90
mass number
total number of protons and neutrons in the nucleus of an atom (top)
91
how do you find the # of neutrons
atomic number - mass number (bottom-top)
92
atomic mass
total mass of the atom
93
isotopes
- when all atoms of a given element have the same number of protons
- buttt some of the atoms have more neutrons (and a greater mass)
- essentially are different forms of the same element
94
radioactive isotope
- nucleus spontaneously decays => gives off particles of energy
- isotopes are unstable, nuclei lose subatomic particles
95
what happens when radioactive decay causes a change in the number of protons in an isotope
the atom transforms to that of another element
96
radioactive tracers
used to follow chemical processes of an organism and diagnose problems (but is dangerous)
97
radiometric dating
used to measure radioactive decay of fossils in order to date them
98
half life
when a parent isotope decays into its daughters isotope at a steady rate (time it takes for 50% of the parent isotope to decay)
99
when 2 atoms approach eachother during a chemical reaction, how do their nuclei behave
they do not interact because they do not come close enough to. most of an atom is empty space
100
what subatomic particle is directly involved in reactions
electrons
101
what is energy and how does it relate to electrons
energy is the capacity to do work. electrons of an atom vary in energy levels
102
what is potential energy and how does it relate to electrons in the nucleus
- energy that matter has because of its location or structure
- matter tends to move towards the lowest area of potential energy
- potential energy results from an electrons distance from the nucleus
- the further away the electrons are from the nucleus, the greater the potential energy (takes for work to keep them further away)
103
energy levels
electrons exist at specific energy levels
- closer to the nucleus = less energy
- further away from the nucleus = more energy
104
what are electron shells
electrons live here, each shell has a unique distance and energy level
105
can electrons move from one shell to another? if so, how?
yes, BUT only by absorbing or loosing energy equal to the difference of PE between positions
- absorbing energy = moving out
- loosing energy = moving in
106
how is chemical behavior determined?
by the distribution of electrons in the electron shells (mostly the outer shell)
107
periods on the periodic table
elements are arranged in 3 rows, and they correspond to the number of electron shells in their atoms
108
1st shell
this is the lowest electron shell (2 electrons)
109
3rd shell
highest electron shell (up to 18)
110
how many electrons does the 2nd shell hold
8
111
valence electrons
electrons in the outermost shell
112
valence shell
the outermost electron shell
113
electron orbitals (definition)
the 3D space where an electron is found 90% of the time
114
what is the reactivity of an atom dependant on
unpaired electrons
115
atoms with incomplete valence shells...
can interact with certain other atoms so that it can complete its valence shell
116
methods of completing a valence shell (2)
sharing or transfering valence electrons
117
strongest kinds of bonds (for covalent and ionic)
- covalent=in molecules
| - ionic=dry ionic compounds
118
covalent bonds
the sharing of a pair of electrons by 2 or more atoms
119
double bonds
when atoms form a molecule and share TWO pairs of valence electrons
120
bonding capacity
when an atom has a full valence shell of electrons (usually equal to the number of electrons needed to complete it)
121
electronegativity
attraction for a particular atom for the electrons of a covalent bond
122
the more electronegative an atom is . . .
the stronger is pulls on shared electrons towards itself
123
when is electronegativity the same in both atoms?
non polar covalent bonds, because they share electrons
124
polar covalent bonds
when bonds are not shared equally and one atom is more electronegative
125
polar covalent bonds
when bonds are not shared equally and one atom is more electronegative
126
ionic bonds
when 2 atoms are so unequal in the attraction for their valence electrons that the more electronegative one strips an electron away from its partner
127
ions
the 2 resulting, oppositely charged atoms after an ionic bond
128
cation
+ ion
129
anion
- ion
130
cation+anion
attracted to eachother, form ionic bonds
131
what are the advantages of weak bonds (ones that arent covalent between molecules)
they can effect eachother, but then seperate
132
important weak interactions
hydrogen bonds, vanderwaals interactions, ionic bonds in water
133
hydrogen bonds
- an H+ ion covalently bonds to an electronegative atom
- partial + charge of H+ attracts a negative charge and a noncovalent attraction occurs
- usually takes place between oxygen or nitrogen in living cells
134
van der waals interactions
when electrons are not evenly distributed => can accumulate by chance in one part of a molecule
- ever-changing regions of postive/negative charge that allows atoms+molecules to stick to one another
- only occurs when atoms/molecules are very close together
135
how are molecules aranged when there are 2 or more of them
they are always linear
136
how are shapes of molecules determined
by the positions of the atom's orbitals
137
what happens to the atoms when a covalent bond is formed
the orbitals in the valence shell undergo rearrangement
138
what happens when molecules with atoms in both s and p orbitals form covalent bonds
4 new hybrid orbitals shaped like teardrops extend from the nucleus (tetrahedron with a triangle base)
139
why is molecular shaoe important
it determines how biological molecules recognize and respond to one another
140
chemical reactions
the making and breaking of chemical bonds => changes in composition of matter
141
reactants
starting materials
142
products
resulting materials
143
how far out can the point of equilibrium be
some are so far out that reactions almost go to completion
144
is water polar or nonpolar
polar
145
what types of charges do O and H have
- o has a partial negative charge
| - H has a partial positive charge
146
how is water bonded and why
water forms hydrogen bonds because the weak attractions between oppositely charged O and H
147
how does water bond in the liquid form
hydrogen bonds are constantly breaking and reforming, which allows molecules to slip closer together
148
how does water bond in the solid form
- hydrgen bonds are stable
- water molecules are further apart
- ice is less dense than liquid and floats
149
what does floating ice do to the water below
insulates it, promoting aquatic life
150
what are polar covalent bonds
b/c oxygen is more electronegative than hydrogen, electrons of the covalent bond spend more time closer to the oxygen
151
why is water a polar molecule
b/c the electrons are unequally shared and the molecule is V shaped
-overall charge is unevenly distributed
152
properties of water
properties arise from the attraction between oppositely charged atoms of different water molecules
- held together by hydrogen bonds
- in liquid form, bonds are very fragile
- bonds break and reform VERY often
153
What are the 4 emergent properties of water
- cohesion
- high surface tension
- cohesion and the transport of water against gravity in plants
- adhesion
154
cohesion of water molecules
hydrogen bonds hold water together collectively
155
high surface tension
hydrogen is bonded to one another and to the water below but not to the air above
-the asymmetry gives high surface tension
156
cohesion and the transport of water against gravity in plants
water goes from the roots to the leaves through a network of water conducting cells
- water evaporates from the leaf, leaves the veins to tug molecules further down because of the hydrogen bonds
- an upward pull is transmitted through the water conducting cells to the roots
157
adhesion
the clinging of one substance to another
-because of the H+ bonds in water, adhesion of water to the molecules of a cell wall helps counter the downward pull of gravity in cohesion transport
158
photosynthesis, reactants and products
process that is the foundation of life
reactants: 6CO2 + 6H2O
products: C6H12O6 + 6O2
159
are all chemical reactions reversible?
theoretically, all chemical reactions are reversible
160
the greater the concerntration of reactant molecules...
the more frequently they collide and react to form products
161
what happens as products in chemical reactions accumulate
collisions resulting in reverse reaction become more frequent
162
chemical equillibrium
when reactions/reverse reactions offset eachther
163
how does water moderate air temp
by absorbing heat from air that is warmer and releasing stored heat to air that is cooler
164
kinetic energy and the relationship with molecules
the faster molecules move, the greater their kinetic energy
165
thermal energy
the kinetic energy associated with the random movement of atoms/molecules. passes from warmer to cooler until the 2 reach the same temp
166
temperature
represents the average kinetic energy of the molecules in a body of matter
167
difference between thermal energy and temperature
thermal energy reflects the TOTAL kinetic energy, temperature reflects AVERAGE kinetic energy
168
heat
when thermal energy is transfered from one body of matter to another
169
calorie
amount of heat it takes to raise the temp of 1g of H2O by 1* C
-also the amnt of heat that 1g of H2O releases when it cools by 1*C
170
kilocalorie
1kg=1*C (same as calorie but in kgs)
171
joule (cals and joules conversion)
equals .239 cals
| 1 cal=4.184 J
172
Waters specific heat
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temp by 1 degree
-H2O changes its temp less often because much of the heat is used to disrupt hydrogen bonds before the water molecules can begin moving faster
173
what happens when the temp of water drops slightly
H bonds form and release energy in the form of heat
174
evaporative cooling
stabilizes the temp of H2O
175
how does evaporative cooling work
- molecules moving fast enough to overcome attraction can depart the liquid and enter the air as gas
- some evaporation occurs at any temperature, but when liquid is heated the average KE of molecules increases and the liquid evaporates more rapidly
176
heat of vaporization
the quanitity of heat a liquid must absorb for 1 gram of it to be converted from a liquid to a gas
177
heat of vaporization of water
1g of H2O @ 25*C needs 580 cals of heat
178
why does H2O have a high heat of vaporization
due to the strength of hydrogen bonds
179
why does ice float on liquid water
water expands when it solidifies instead of contracting/becoming denser
180
solution
a mixture (homogenous) of 2 or more substances
181
solvent
dissolving agent
182
solute
the substance that is dissolved
183
aqueous solution
solute is dissolved in water
184
why is water a versitile solvent
because of its polarity
185
hydration shell
a sphere of water molecules around each dissolved ion
186
what can be dissolved in water
anything, as long as the molecules have an ionic and polar region
187
hydrophilic
likes water
188
hydrophobic
scared of water, nonpolar, nonionic
189
are hydrophilic substances dissolvable
not always ex) cotton towels
190
how are hydrophobic substances bonded
nonpolar covalent bonds
191
molarity
of moles of solute per liter of solution (and unit of concentration for aqueous solutions
192
mole
number of molecules in a substance
193
buffer
an acid-base pair that combines reversibly with hydrogen ions, allowing it to resist pH changes
194
ocean acidification
fossil fuels are burned => increase CO2 => CO2 dissolves in ocean
195
carbon chemistry
specializes in the study of carbon
196
electrons in carbon
```
2 in first shell
4 in second shell
4 empty electron spots in second shell
valence number = 4
total electrons = 6
```
197
what are carbon's bonding patterns
carbon shares electrons with other atoms to complete its outer shell (very little tendency to gain or lose electrons/form ionic bonds)
198
hydrocarbons
organic molecules consisting of only carbon and hydrogens
199
isomers
compounds that have the same molecular formula but different structure and therefore have different properties
200
what are the 3 classes of isomers
- structural isomers
- geometric isomers
- enantiomers
201
structural isomers
differ in the arrangements of their atoms
202
geometric isomers
cis-trans
203
entantiomers
mirrored
204
functional groups
components of organic molecules that are most commonly involved in chem reactions (bonded to carbon skeleton)
205
6 functional groups
```
hydroxyl
carbonyl
carboxyl
amino
sulfhydryl
phosphate
methyl
```
206
hydroxyl
- OH
- ex)alcohols
- polar (O is electroneg)
- water is attracted to these
207
carbonyl
=O (double bond)
- aldehyde (on end of carbon skeleton)
- ketone (in middle of carbon skeleton)
- polar
208
carboxyl
- COOH
- carboxylic acids
- have acidic properties because H+ tends to dissociate
- covalent bond between H and O are VERY polar
209
amino
- NH2
- amines
- act as bases
- commonly attract H+ ions, giving it a + charge
210
sulfhydryl
- SH
- thiols
- stabilizes the structure of proteins
211
phosphate
- PO4-
| - important for the transfer of energy between organic compounds
212
methyl
- CH3
- methylated compounds
- nonpolar
- adding a methyl group to DNA affects gene expression
213
what makes carbon the basis for all biological molecules
- can form 4 bonds (with other atoms/groups of atoms)
| - can bond to other carbons (carbon skeleton)
214
what does ccarbon commonly bond with
- hydrogen
- oxygen
- nitrogen
215
organic chemistry
- carbon containing compounds = organic
| - study of these
216
what kind of bonds do carbons form
a covalent bond
217
what kind of molecules does carbon form and why
- large, complex molecules
| - b/c molecules can branch out from a carbon in as many as 4 directions
218
what shape will carbon be in 4, singular&covalent bonds
tetrahedron
219
what shape will carbon be in for 2, double bonds
both carbons will be in the same plane (molecule is flat)
220
shapes of carbon skeletons
- vary in length
- straight
- branched
- closed ring
221
what constitutes carbon's molecular complexity in living matter
-some have double bonds that vary in number and location => variation in carbon chains
222
hydrocarbons
organic molecules consisting of only carbon and hydrogen
223
how are hydrocarbons bonded
covalently
224
characteristics of hydrocarbons
- hydrophobic
| - do not dissolve in water
225
characteristics of a cis-trans isomer
- atoms differ in spacial arrangement due to the inflexibility of double bonds
- single bonds allow atoms to rotate freely without changing the compound
- double bonds to not rotate
226
characteristics of an enantiomer
- 4 groups can be arranged in space around asymmetric carbon in 2 different ways, which forms mirror images
- only 1 is usually biologically active (only that 1 form can bond to specific molecules)
227
why are phosphate groups key to molecular function
- because ATP!
| - ATP is made up of an adenosine attached to a string of 3 phosphate groups
228
monomer
1 building block of a polymer
| -small repeating molecules
229
polymer
more than 1 monomer joined together to make a large molecule
| -long molecules consisting of many identical or similar building blocks linked by covalent bonds
230
polymers and their monomers (biological molecules)
- proteins/amino acids
- carbohydrates/monosaccharides
- lipids/fatty acids+glycerol
- nucleic acid/nucleic acids
231
dehydration reactions
removes a water to form a new bond
232
hydrolysis
adds a water to break a covalent bond
- chemical reactions responsible for the disassembly of polymers
- reverse if dehydration reactions
233
carbohydrates
main source of energy in living organisms
234
types of saccharides (4)
- monosaccharides
- disaccharides
- trisaccharides
- polysaccharides
235
what is the general structural formula of monosaccharides
(CH2O)n
236
pentose
5 carbon sugar
237
ribose
RNA (has extra oxygen from the hydroxyl group at its 2nd carbon)
238
deoxyribose
DNA (only hydrogen at the 2nd carbon)
239
how are disaccharides bonded
glycosidic linkage (covalent bond)
240
structure of disaccharides
2 glucose molecules and a loose H2O molecule
241
what are the 3 important disaccharides
- maltose
- sucrose
- lactose
242
maltose
glucose+glucose
243
sucrose
glucose+fructose
244
lactose
glucose+galactose
245
starch
energy storage form of glucose in plants
246
cellulose
major component of plant cell walls
247
lipids
3 fatty acids and 1 glycerol
248
lipids
3 fatty acids and 1 glycerol
249
saturated fatty acid
only single bonds
250
unsaturated fatty acids
1 double or triple bond in the chain
251
polyunsaturated fatty acid
more than 1 double or triple bond in an ester linkage
252
biologically relevant lipids
phospholipids and steroids
253
in a condensation/dehydration reaction, how do the molecules contribute to the loss of a water molecule
- one molecule contributes the -OH group
| - one molecule contributes the -H group
254
carbohydrates
main source of energy: sugars (saccharides)
255
what are the 3 types of saccharides
mono
di
poly
256
about monosaccharides
- simple sugar
| - general structure (CH2O)n
257
hexose
monosac
| 6 carbon sugars
258
pentose
monosac
| 5 carbon sugar
259
glucose
C6H12O6
| aldose sugar
260
fructose
C6H12O6
| ketose sugar
261
disaccharides
two simple sugars joined together
262
glycosidic linkages
a covalent bond formed between 2 monosaccharides by a dehydration reaction
263
sucrose
(disac)
| glucose+fructose
264
maltose
(disac)
| glucose+glucose
265
lactose
glucose+galactose
266
polysaccharides
more than 2 simple sugars joined together
267
what are the biologically important polysaccharides
- starch
- glycogen
- cellulose
- chitin
268
starch
storage form of glucose in animals
alpha glucose=(-OH group of C1 is down)
1-4 linkages
269
glycogen
storage form of glucose in plants
alpha glucose=(-OH group of C1 is down)
1-4 and 1-6 linkages
270
cellulose
major components of plant cell walls
polymers of beta glucose (-OH group on C1 is up)
1-4 linkages
271
chitin
component of arthropod exoskeleton (invertabrates), and the cell wall of some fungi
beta-glucose (-OH group on C1 is up) with nitrogen appendages
272
fatty acids
the building blocks of lipids: long chains of carbon atoms with associated hydrogen
273
saturated fatty acids
chains of carbons with single bonds
274
unsaturated fatty acids
chains of carbons with one double or triple bonds (makes a kink in the chain)
275
polyunsaturated fatty acids
chains of carbons with more than one double or triple bonds
276
long chains of hydrocarbons and their relationship with water
no affinity for water
277
basic structure of lipids
- 3 fatty acid chains bonded by an ester linkage (long carbon skeleton of 16-18 carbons in length
- 1 glycerol (3 carbon alcohol)
278
structure of phospholipids
- 2 fatty acid chains and a phosphate group joined to a glycerol
- amphipathic (both hydrophilic and hydrophobic parts)
279
what is the charge and polarity of the phosphate group in phospholipids
negative charge, polar
280
what is the charge and polarity of fatty acid groups
uncharged and nonpolar
281
micelles
aggregate of phospholipids that form when they are put into an aqueous solution
282
phosphate heads
exposed to water
283
carbon tails
are shielded from the water
284
importance of phospholipids
they form cell membranes/lipid bilayers
285
steroids
lipids characterized by a carbon skeleton consisting of 4 fused rings
- different steroids have different functional groups attached to the rings
- vertebrate sex hormones
286
cholesterol
common component of animal cell membranes, precursor from which other steroids are synthesized
287
proteins
made of amino acids joined together by peptide bonds
288
how many amino acids are there that make up proteins
20
289
amino acid structure
- amine group
- carboxyl group
- R group (gives each amino acid different chemical properties, like polar/nonpolar/acid/base)
290
what are 2 amino acids bonded together called, and how are they bonded
dipeptide, bonded by peptide bonds
291
what is it called when many amino acids are bonded together
polypeptide
292
primary structure
a linear sequence of amino acids
293
secondary structure
- alpha helix
| - beta pleated sheets
294
primary structure
a linear sequence of amino acids
295
secondary structure
- alpha helix
| - beta pleated sheets
296
alpha helix
forms dur to hydrogen bonding every 4th amino acid in primary structure
297
beta pleated sheet
due to hydrogen bonding between 2 sections of the primary structure that are aligned parallel to eachother
298
tertiary structure
irregular contortions from bonding between R-groups of the various amino acids
299
hydrophobic interactions
amino acids with non-polar R-groups tend to cluster in the center of the protein
300
how do hydrogen bonds form in tertiary structure
between polar side chains
301
how do ionic bonds form in tertiary structure
between positive (base) and negative (acid) charged R-groups
302
what force is betwee R-groups in tertiary reactions
vanderwaals forces
303
disulfide bridges
covalent bonds between sulfur groups in the R-group of amino acid cystein
304
quaternary structure
overall protein structure that results from the aggregation of polypeptide units
305
collagen
3 polypeptides that aggregate to form a triple helix
306
hemoglobin
consists of 2 kinds of polypeptide chains, with 2 of each kind per hemoglobin molecule
307
what are the 2 classes of proteins
structural proteins
| functional proteins
308
function of structural proteins
cell structure
309
clases of functional proteins
- enzymes
- transport proteins
- hormones
- receptor proteins
- contractile/motor proteins
- defense proteins
310
what determines protein conformation
a polypeptide chain of a given amino acid sequence can spontaneously arrange itself into a 3D shape maintained by the above interactions
-also depends upon the physical and chemical conditions of the proteins environment (pH, salt concentration, temp)
311
denaturation
unraveling of protein structure due to adverse environmental conditions, the protein is said to be inactive
312
Nucleic acids
DNA
| RNA
313
structure of nucleic acids
- composed of chains of monomers called nucleotides
- pentose sugar (deoxyribose/ribose)
- nitrogenous base: pyrimidine (6 membered ring fused to a 5 member ring) (adenine and guanine)
- phosphate group
314
nucleosides
pentose sugar + nitrogenous base
315
nucleotides in DNA
GATC
316
nucleotides in RNA
GAUC
317
polynucleotide structure
anti-parallel double helix (5'/3' ends)
- base pairing via hydrogen bonds (DNA=A-T G-C) (RNA= A-U G-C)
- 2 H bonds between A and T and 3 H-bonds between C and G
318
organelles
tiny sacs and compartments bounded by membranes
319
what characteristics do both euks and proks share
- outer plasma membrane
- internal region of DNA
- cytoplasm
320
plasma membrane
forms boundaries between cell and external environment
- phospholipid bilayer
- contains sterols(cholesterol)
- contains proteins for transport and recognition
321
phospholipid bilayer
- hydrophilic end
| - hydrophobic end
322
fluid mosaic model
plasma membrane is a fluid structure with a mosaic of various proteins embedded in it
the fluid nature of the membrane allows the proteins and phospholipids to move in the horizontal plane without losing the membrane's integrity
323
nucleus
contains DNA organized into chromosomes, existing in the form of chromatin (a DNA histone complex)
- membrane
- nuclear pores
- nucleoli
- nucleoplasm
324
membrane in nucleus
bound by a double lipid bilayer-nuclear envelope
325
nuclear pores
highly selective to protect chromosomes
326
nucleoli
synthesis of ribosomes
327
nucleoplasm
cytoplasm of nucleus
328
characteristics of cytoplasm
- within plasma membrane but outside of nucleus
- cytosol (the watery substances supporting organelles
- contains metabolic machinery (organelles, enzymes, etc)
329
mitochondria
```
energy center (powerhouse of the cell)
-forms ATP through the electron transport system
```
330
how many membranes does the mitochondria have
2, one outer and one inner that folds and forms cristae
331
why are cristae important
they increase the surface area of the membrane to permit increased ATP production
332
what does the double membrane in mitochondria create
matrix-space inside the inner membrane
| intermembrane space-space between the inner and outer membrane
333
ribosomes
- composed of rRNA and r-proteins
| - used to make protein from DNA
334
endoplasmic reticulum
circulatory system of the cell
335
smooth ER
lipid assembly/modification and transport
- carbohydrate metabolism
- detoxification of drugs and poisons
336
rough ER
protein assembly/modification and transport
- bounded by ribiosomes
- stores proteins
337
golgi apparatus
recieves protein from ER (cis end) and further modifies
| -packages proteins for transport either within or external to cell (trans end)
338
lysosomes
- contains hydrolytic enzymes that digest macromolecules
- bind with vesicles containing ingested materials (food, bacteria) and break it down
- autophagy
339
autophagy
recycling of cells own organic materials derived from damaged materials
340
peroxisomes
- contains enzymes that transfer hydrogens from (usually toxic) substances to oxygen creating hydrogen peroxide
- detoxifies alcohol
- converts hydrogen peroxide to water because hydrogen peroxide is toxic
341
vacuoles/vesicles
- vesicles are smaller vacuoles
| - transport, storage
342
cytoskeleton
gives mechanical support to the cell, anchors organelles in the cytoplasm
- aids in cellular molarity
- helps to maintain its shape
- made up of 3 types of fibers
343
what are the 3 types of fibers in the cytoskeleton
- microtubules
- microfilaments
- intermediate filaments
344
microtubules
shape and support the cell and serve as tracks along which the organelles can move
345
microfilaments/actin
bear tension within the cell
| -help support the cell's shape and are involved in cell motility
346
intermediate filaments
-specialized for bearing tension and fixing the position of organelles, especially the nucleus
347
centrosomes
- microtubules organizing center for cell division
| - composed of 2 centrioles (9 triplet microtubules) arranges in a ring
348
what organisms lack centrosomes
-plant and yeast cells lack centrosomes
349
flagella
- composed of microtubules
- external to plasma membrane
- provide motility
350
cilia
- composed of microtubules
- shorter and more numerous than flagella
- used in movement of protozoa (single celled euks)
351
how do cilia work in humans
ciliate cells move mucous and materials past the cell for expulsion
352
pseudopodia
- false feet
- composed of microfilaments
- projections of cytoplasm which creates ameboid movement
- used in human phagocytes to engulf foreign material
353
what are the organelles that are specific to plants
```
chloroplast
central vacuole
tonoplast
cell wall
protoplast
plasmodesmata
middle lamella
```
354
chloroplast
- site of photosynthesis
| - envelope of 2 phospholipid bilayers (inner and outer), separated by an intermembrane space
355
structures in the chloroplast
```
stroma
thylakoid membranes
grana
chlorophyl
thylakoid space
```
356
stroma
space between the envelope and the thylakoid membrane
357
thylakoid membranes
"pancake stacked" membranes that separate the stroma from the thylakoid space (or lumen)
358
grana
the "pancake stacks" that increase surface area
359
chlorophyll
resides in the thylakoid membranes
360
thylakoid space
space inside the thylakoid membrane
361
central vacuole
contains sap; nounded by the tonoplast
362
tonoplast
membrane that regulates the traffic of molecules between the sap and the cytosol
363
cell wall
external to the plasma membrane
364
primary cell wall
all plant cells have; secreted as the cell grows and develops
365
secondary cell wall
produced by certain specialized plant cells; closer to the protoplast than the primary wall because it forms after the cell has stopped growing: provides protection and support
366
protoplast
are spherical naked plant cells produced by the removal of the cell wall with digestive enzymes
367
plasmodesmata
cytoplasmic channels that pass through pores in the cell walls allowing the protoplasts of neighboring cells to be connected
368
middle lamella
adhesive layer that cements together the cell walls of the adjacent cells
369
prok cell structure
- bacteria and archeae are considered proks
- unicellular
- smallest of all organisms (viruses are smaller but acellular)
- bacteria
370
shapes of bacteria
- coccus
- bacillus
- vibro
- spirillum
- spirochete
- pleiomorphic
371
coccus
spheres
372
bacillus
rods/coccobacillus (in between the 2)
373
vibrio
comma shaped
374
spirillum
cork skrew with flagella at one end or both ends
375
spirochete
cork skrew with internal flagella
376
pleiomorphic
bacteria exhibiting many shapes
377
patterns of bacteria
cocci and bacilli
378
types of cocci
- diplococci
- staphylococci
- streptococi
- tetrad
- sarcinae
379
diplococci
pairs
380
staphylococci
clusters
381
streptococci
chains
382
tetrad
4 cell cube
383
sarcinae
8 cell cube
384
types of bacilli
bacillus and palisade
385
bacillus
chains
386
palisade
bacilli side-by-side
387
cell/plasma membrane function/structure kinda
forms boundary between cell and external environment
| -contains proteins for transport
388
what does the bacterial cell membrane lack
sterols (cholesterol) but they contain sterol-like molecules called hopanoids
389
characteristics of the cell wall
- lies outside the cell membrane
- porous
- maintains integrity of cell shape
- main component is peptidoglycan (murein)
390
cross linking
a bond that links 1 polymer chain to another
391
what type of amino acid can not be broken down by common enzymes
stereoisomers of common amino acids
392
gram +
thick peptidoglycan wall
393
gram -
thin peptidoglycan wall
394
characteristics of the outer membrane of prok cells
- gram -
- attached to the cell wall and lipid bilayer
- contains lipopolysaccharide (LPS)
- core polysaccharide
- o antigen
395
lipid A
embedded in the outer membrane
| -stabalizes outer membrane structure
396
abt O antigen
displays antigen variation
397
periplasmic space
- gap between the cell membrane and the cell wall
- includes peptidoglycan, enzymes, and proteins which makes up the periplasm
- serves as a site for transport of nutrients protection
398
protoplasts and spheroplasts
-the cell wall protects bacteria from osmotic lysis when they are in a hypotonic solution
399
what does digestion of cell wall in gram + yield
protoplasts
400
what does digestion of cell walls in gram - yield
spheroplasts
401
cytoplasm
- watery substance in the cell
- contains metabolic machinery like proteins and DNA
- determines cell shape
402
nuclear region (nucleoid)
contains compacted DNA with some associated protein (not histones) and RNA
403
plasmids
extra chromosomal DNA
404
types of plasmids
- conjugative plasmids
- col plasmids
- virulence plasmids
- metabolic plasmids
405
conjugative plasmids
F plasmids and R plasmids
406
col plasmids
produce bacteriocins
407
virulence plasmids
encode virulence factors
408
metabolic plasmids
encode degradiative enzyme
409
cytoskeleton
homologs of all 3 eukaryotic cytoskeletal components have recently been identified in bacteria (microtubules, microfilaments and intermediate filaments)
410
functions of the cytoskeleton
- participate in cell division
| - localize proteins to certain sites within the cell
411
ribosomes
- RNA & protein structures that ain in synthesizing protein
- euks: 80S
- proks: 70S
412
what does "S" mean
suedberg unit; sedimentation coeficcient measure of sedimentation velocity in a centrifuge
413
inclusion granules
storage pools of required metabolites
- stores glycogen and glucose
- stores volutin and polyphosphate
414
capsule
well organized and not easily washed off
415
slime layer
more diffuse and can easily be removed
416
similarities of the capsule and the slime layer
both are external to the cell wall and can be called glycocalyx
417
functions of the capsule and the slime layer
- prevents phagocytosis
| - aids in adherance to host tissues
418
pili/fambriae
-hollow projections
419
what are the 2 types of fili/fambriae
conjugation pili and attachment pili
420
conjugation pili
transfer of genetic material
421
attachment pili/fambriae
attach to surfaces like cells and water
422
flagella
- external to cell wall
| - provide motality
423
key base word of flagella
trichous
424
flagella prefixes
- mono: 1
- amphi: 1 at each end
- lopho: 2 or more at one or both ends
- peri: all over surface
- a:none
425
clockwise flagella movement
direct movement
426
counter clockwise flagella movement
random movement
427
chemo movement
move toward (positive) or away (negative) from chemical substances
428
photo movement
toward or away from light
429
aero movement
toward or away from oxygen
430
osmo movement
move toward or away from osmotic pressure
431
vegetative cells
cells that are actively metabolizing
432
spore formation
occurs under harsh conditions
433
dormant state
form within the cell
434
endospores
highly resistant to environmental conditions, contains little water, resistant to heat
435
sporulation
when conditions are right, the spores will germinate=begin to develop into vegetative cells again
436
cell-cell recognition
a cells ability to distinguish one type of neighboring cell from another
437
oligosaccharides
are on the external side of the plasma membrane, they vary from cell to cell and species to species
438
what enables oligosacs to function and how do they function?
the diversity of molecules and their location on the cell's surface. the oligosacs function as markers that distinguish one cell from another
439
enzymatic activity
a protein embedded into the membrane with enzymatic activity
440
what happens when there are several enzymes in a membrane
enzymes are ordered as a team that carries out sequential steps of a metabolic pathways, like in the mitochondria
441
signal transduction
membrane protein with a b inding site for a chemical messenger such as a hormone
442
what happens upon the protein bonding to a messanger
a signal is transmitted to the interior of the cell
443
extracellular matrix (ECM)
the substance in which animal tissue cells are embedded
- consists of proteins and polysaccharides
- helps to maintain cell shape, anchor cells in a specific location, stabilizes membrane proteins
444
what are the functions of plasma membrane proteins
- cell/cell recognition
- enzyme activity
- signal transduction
- intracellular joining (gap junctions, etc)
- attachment to cytoskeleton and extracellular matrix
- transport
445
semi permeable membrane
ability of membranes to selectively permit certain substances to cross it over other substances
446
hydrophobic phospholipid tails
core of the membrane. is the main barrier for transport across the plasma membrane
447
molecules that can cross the plasma membrane
```
-hydrophobic molecules: dissolve into the hydrophobic core of the membrane, enabling them to cross it
ex)
-hydrocarbons
-CO2
-O2
```
448
molecules that cannot cross the plasma membrane
-hydrophilic molecules
ex)
-charged ions
-polar molecules
-large, uncharged and polar molecules (too big)
ex)
carbs
proteins
449
transport proteins
proteins that span the membrane that permit the transit of ions, polar molecules and larger molecules across the membrane
450
what type of structure do transport proteins usually have
hydrophilic channels
451
aquaporins
transport proteins that transport water
452
diffusion
the tendancy for molecules of any substance to spread out into available space from a high to low concentration (downhill)
453
concentration gradient
a gradient of different concentrations of a solute in a solutions
454
dynamic equilibrium
occurs when the concentration of solutes is equal access a membrane. There is no net charge in solute movement across the membrane but the solutes are still moving
455
what must NOT happen in order for diffusion to occur
NO WORK must be done to make diffusion happen, it is a spontaneous process and delta G is negative
456
passive transport
the diffusion of substances across a biological membrane
457
what does the cell NOT do in passive transport
the cell does NOT expend energy
458
facilitated diffusion
the passive transport of ions and polar molecules that cannot cross the semipermeable membrane on their own
459
what is required in facilitated diffusion
a transport protein is required, it just serves as a hydrophilic channel
460
osmosis
diffusion of water across a semi-permeable membrane (aka the passive transport of water)
461
hypertonic solution
the solution has a higher solute concentration that the animal cell
462
what happens in a hypertonic solution
water exits the cell and the cell shrinks
463
hypotonic
a solution that has a lower solute concentration than the animal cell
464
what happens in a hypotonic solution
the cell gains water and the cell could lyse
465
isotonic
both solutions have the same solute concentration
466
how do water molecules move
from a hypotonic solution to a hypertonic solution
467
if a cell is placed in a hypertonic solution, what happens to its membrane?
plasmolysis: as the plant cell shrivels, the plasma membrane pulls away from the cell wall
468
if a cell is placed in a hypotonic solution, what happens to its membrane
turgid-the cell takes up water until it is full and the turgid cells give a plant its structure
469
what happens to the membrane when a cell is placed in an isotonic solution
it is flaccid and there is no net movement of water, so the membrane becomes limp and wilts
470
active transport
the transport of solutes against their concentration gradients
471
what does active transport require
active transport requires energy
472
transport of large molecules
exocytosis, endocytosis
473
exocytosis
fusion of vesicles derived from the golgi apparatus with the plasma membrane => extrusion of macromolecules
ex) hormones, insulin
474
endocytosis
the taking in of macromolecules by forming vesicles derived from the plasma membrane through the process of phagocytosis, pinocytosis, receptor-mediated endocytosis
475
phagocytosis
uptake of particles by wrapping pseudopodia around it and packaging it within a vacuole
476
pinocytosis
the cell gulps droplets of extracellular fluid in tiny vesicles
477
receptor mediated endocytosis
endocytosis of specific molecules that bind to membrane bound receptors
478
steroids
4 fused hydrocarbon rings
479
why is cholesterol important
b/c it is important in cell membrane structure
480
what is the precursor molecule for all other human steroids
cholesterol
481
how are proteins made in euk cells
DNA => mRNA => ribosomes +cytoplasm
| occurs mostly in the nucleus
482
how are proteins made in prok cells
everything occurs in the cytoplasm because theres no membrane bound organelles
483
when do H bonds occur
every 4th amino acid, below the polar R-groups,
484
what do H bonds do to the helix structure
stabilizes the alpha helix structure
485
folding
FOLDING IS NOT RANDOM, it is due to the amino acids in the polypeptide
486
what are the types of bonds that hold tertiary structure together
- hydrophobic interactions
- hydrogen bonding between R groups
- ionic bonds below acidic + charges
- disulfide bridges
487
hydrophobic interactions
amino acids with non polar R-groups will cluser inside of the globular protein
488
disulfide bridges
covalent bonds below R groups of cystein amino acids
489
4 prime structure
multiple 3 prime proteins are bound together to create a large functional protein molecule
490
chaperonin
helps 2 prime => 3 prime and 3 prime => 4 prime
491
what are chaperonins made by
other chaperonins
492
what are the types of functional proteins in a cell
- enzymes
- receptor proteins
- transport proteins
- structural proteins
- motor proteins
- defense proteins
- hormones
493
what determines protein structure
environment and function
494
denaturation
process by which protein structure unfolds. this is irreversible, protein is nonfunctional b/c there is no chaperonins or DNA
495
mRNA
codes for proteins
496
RNA
carries amino acids to ribosomes to make a protein
497
rRNA
structural components of the ribosome
498
central dogma
DNA => RNA => protein
499
purines
adenine and guanine
500
perimadines
thymine, cytosine and uricil
501
nucleosides
sugar + base w/o phosphate group
502
what type of bond holds nucleotides together
phosphodiester
503
characteristics of DNA
- double stranded
- antiparallel
- 3' and 5' end
- 2 different strands are oriented in opposite directions
504
a-t
2 hydrogen bonds
505
c-g
3 hydrogen bonds
506
characteristics of RNA
- single stranded (mRNA)
| - tRNA + rRNA have regions of double strandedness
507
characteristics of RNA
- single stranded (mRNA)
| - tRNA + rRNA have regions of double strandedness
508
functions of cell to cell recognition (plasma membrane proteins)
- used to help cells recognize eachother
| - human immune response (recognizing the difference between self and non self)
509
enzymetic activity
plasma membrane proteins that have metabolic functions
510
signal transduction
enables cells to monitor environment + respond
511
metabolism
the totality of an organisms chemical processes
512
catabolic pathways
the metabolic pathways responsible for the breakdown of complex molecules into simpler ones
- energy is released
- cellular respiration
513
cellular respiration
glucose => CO2 + H2O + ATP
514
anabolic pathways
- the metabolic pathways responsible for the build up of complex molecules from simpler ones
- energy is consumed
- photosynthesis
515
photosynthesis
synthesis of a protein from amino acids
516
bioenergetics
study of how organisms manage their energy resources
517
energy
the capacity to do work
518
thermodynamics
study of energy transformations that occur in a collection of matter
519
the first law of thermodynamics
energy can be transferred and transformed, but it can not be created nor destroyed
520
the second law of thermodynamics
every energy transfer or transformation increases the entropy of the universe
521
how do organisms process energy
an organism takes in organized forms of energy from the surroundings and replaces them with less ordered forms of energy
522
free energy
the portion of a system's energy that can perform work when the temperature is uniform throughout the system (=potential energy of the system)
-the energy that is available to do work
523
what are the 2 components of free energy (g)
H: potential + kinetic energy
S: the systems of entropy (randomness)
T: absolute temp in Kelvin units
524
what is the equation for G free energy
G= H-TS
525
chemical rections are of 2 types
- spontaneous
| - nonspontaneous
526
spontaneous reactions
occur spontaneously because the starting materials have either high energy (unstable) or low entropy (not random) or both
- complex macromolecules
- catabolic reactions
527
nonspontaneous reactions
require energy to occur. they do not occur spontaneously because the starting materials have either low energy (stable) or high entropy (random) or both
- monomers
- anabolic reactions
528
free energy in spontaneous reactions
the free energy of a system decreases by either giving up energy (usually in the form of heat) or by increasing randomness
529
what must free energy be in order for a spontaneous reaction to occur
change in G must be NEGATIVE
530
what happens to free energy when chemical reactions reach equilibrium
free energy G = 0
531
exergonic reactions
reactions that occur spontaneously, free energy is negative, and free energy is released (catabolic)
532
endergonic reactions
reactions that do not occur spontaneously, free energy is positive, and free energy is absorbed for the reaction to occur (anabolic)
533
metabolic disequilibrium
because free energy = 0 when the system reaches equilibrium, the system can do no work.
534
what happens when all of the chemical reactions within a cell reach equilibrium
the cell would be dead
535
how do cells prevent equilibrium
use the products of the chemical reactions as quickly as they are produced
536
energy coupling
use of an exergonic process to drive an endergonic one
537
what is responsible for mediating most energy coupling reactions within cells
ATP
538
what happens when the bonds between the phosphate groups are broken by hydrolysis
yields an inorganic phosphate molecule and ADP
539
what does hydrolysis of the high energy phosphate bonds do (exergonic)
releases energy that can be used to drive endergonic reactions
540
how can ATP be regenerated
by the process of cellular respiration
541
enzymes
catalytic proteins that lower the free energy of activation of chemical reactions
542
catalyst
chemical reagent that changes the rate of reaction without being consumed or changed
543
free energy of activation
the initial investment of energy for starting a reaction (the energy that is required to break bonds in the reactant molecules)
544
enzymes and their relationship to substrates
enzymes are substrate specific (lock and key)
545
active site
site on the enzyme in which the substrate interacts (usually through week interaction) and the catalytic reaction occurs
546
stretching and bending of chemical bonds
helps break the bonds that must be broken for the enzyme to bind to the substrate
547
environment for active site
active site may have a specific microenvironment that may be suitable for the reactions (acidic R groups, basic R groups etc)
548
inducible fit
as the substrate enters the active site of the enzyme, it induces the enzyme to change its shape slightly so that the active site fits even more snugly around the substrate
549
factors that affect enzymatic activity
- concentration
- temp
- pH
- cofactors
- enzyme inhibitors
550
concentration
the more enzymes present, the more enzymatic activity (and vice versa)
551
temperature
up to a point, the velocity of an enzymatic reaction increases with increasing temp, partly because substrates collide with active sites more frequently when the molecules move rapidly
552
high temp's affect on enzymatic activity
denaturation (loose structure) of proteins
553
low temp's affect on enzymatic activity
reaction rate decreases because there are less collisions
554
pH affect on enzymatic activity
6-8 is usually optimal
555
cofactors affect on enzymatic activity
non-protein helpers for catalytic activity (vitamins)
556
co-enzymes affect on enzymatic activity
organic molecules that serve as co-factors
557
competitive inhibitors
enzymatic inhibitors that resemble the substrate. they bind the active site and reversibly inhibit the enzyme
558
noncompetitive inhibitors
do not bind to active site, instead bind to another part of the enzyme and causes the enzyme molecule to change its conformation so the substrate can no longer interact with the active site
559
reversible reactions
if inhibitors can be removed
560
irreversible reactions
suicide inhibitor
561
bioenergetics
the study of how organisms manage their energy resources
562
what do biological systems want to do with energy
want to decrease the amount of energy lost as heat because heat can not be used to run chemical reactions. they want to harvest NG as ATP
563
what defines whether or not a chem reaction is spontaneous or nonspontaneous
the characteristics of the starting materials
564
spontaneous reactions
- catabolic
- high energy
- unstable
- low entropy
- organized
- starting materials are polymers
565
nonspontaneous reactions
- anabolic
- starting materials are monomers
- low energy
- stable
- high entropy
- random
566
activation energy
required in all reactions
| initial investment of energy ensuring all reactants are close enough for their bonds to react
567
what do enzymes do to activation energy and why
lower it because they serve as "landing pads" to bring substrate molecules together in 1 place and to expose bonds that need to be worked on to create products
