Unit 2 review Flashcards
(169 cards)
1
Q
make up majority of cells dry weight. Will have components attached (functional groups) made of elements other than C and H
A
carbohydrates, lipids, proteins, nucleic acids
2
Q
All have ratio of C:H:O as 1:2:1, have mono-, di-, and poly-, Function: to get you through until your next meal
A
carbohydrates
3
Q
Fats, oils, waxes, phospholipids and steroids,
usually the smallest of the macromolecules
A
Lipids
4
Q
what are lipids used as
A
long term energy storage (fats), water repellant for aquatic animals, insulation, cushioning for organs, hormones, and structural role in cells
5
Q
of a substance able to be dissolved, especially in water
A
soluble
6
Q
when are lipids soluble
A
NON-polar substances (a molecule where the electrical charges are distributed evenly across the molecule meaning there are no distinct positive or negative poles) - mostly due to non polar C-C and C-H bonds
7
Q
complex lipids that make up cell membranes, major building blocks of all biological membranes, which protects the cell
A
phospholipids
8
Q
A molecule that has both a hydrophilic (water loving) part called the head and hydrophobic (water fearing) part called the tail.
A
amphipathic (phospholipids are amphipathic with a hydrophilic head and two hydrophobic fatty acid tails)
9
Q
what are the functions of proteins
A
enzymes, transport, structural, contraction, antibodies
10
Q
what biological role do proteins have as structural
A
support
11
Q
what biological role do proteins have as storage
A
store amino acids
12
Q
what biological roles do proteins have in regards to enzymes
A
speed up chemical reactions
13
Q
what biological roles do proteins have in regards to contractile
A
movement (muscle gets tighter or smaller)
14
Q
what biological roles do proteins have for defense
A
protection against disease
15
Q
what biological roles do proteins have for receptors
A
found in cell membranes and help transmit signals to other cells
16
Q
what biological roles do proteins in regards to transport
A
help move substances into and out of the cell
17
Q
what are proteins made of
A
amino acids
18
Q
what are amino acids
A
organic compounds that have amino and carboxylic acid groups. They all have 3 groups in common around an alpha carbon. (amino group and carboxyl group connected to a side chain. 3 groups)
19
Q
what is the primary structure of protein
A
amino acids
20
Q
what is the secondary structure of proteins
A
alpha helixes and pleated/beta sheets
21
Q
what is the tertiary structure of proteins
A
overall shape of single polypeptide chain (combo of pleated sheet and alpha helix)
22
Q
what is the quaternary structure of a protein
A
the arrangement of multiple polypeptide chains to form a protein
23
Q
what are nucleic acids
A
chemical compounds that serve as the primary information carrying molecules within cells
24
Q
what are the two main types of nucleic acids
A
DNA and RNA
25
what is the concept that genetic info flows from DNA to RNA to protein
central dogma in biology
26
process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities (work)
nutrition
27
must be provided to an organism from environment
essential nutrients
28
which category of essential nutrients: required in large quantities; play principal roles in cell structure and
metabolism. these are proteins, carbohydrates
macronutrients
29
which category of essential nutrients: required in
small amounts; involved in enzyme function
and maintenance of protein structure. These are manganese, zinc, and nickel for example
micronutrients
30
contain carbon and hydrogen atoms and are usually the products of living things (carbohydrates, lipids, proteins, and nucleic acids).
organic nutrients
31
atom or molecule that contains atoms other than carbon and hydrogen. metals and their salts, sulfate, ferric nitrate, sodium, gases, carbon dioxide, water
inorganic nutrients
32
must obtain carbon in an
organic form made
by other living
organisms (animals most microbes
heterotroph carbon source
33
– an organism that uses
CO2, an inorganic gas as its carbon source. not nutritionally dependent on other living things
Autotroph carbon source
34
which major nutritional type of energy source from electrons: gain energy from chemical compounds (may be auto- or hetero-)
chemotroph
35
chemotroph type that uses inorganic chemical
compounds (H2, H2S, etc.) “rock eaters”
lithotrophs
36
chemotroph type that uses organic chemical
compounds (sugars)
organotrophs
37
which major nutritional type of energy source from electrons: gain energy by absorbing light
phototrophs
38
use photosynthesis (light + water + CO2 = food)
photoautotrophs
39
Must obtain organic compounds
because they lack the genetic and
metabolic mechanisms to synthesize them
growth factors, essential amino acids, vitamins
40
Regulates molecules (except for water and gasses
like O2 and CO2 which can diffuse in and out
freely)
phospholipid bilayer of the cell (structure of the plasma membrane)
41
Serve as the gates to let desirable substances in
and push waste substances out
proteins -structure of the plasma membrane
42
The Movement of
Chemicals Across the Cell
Membrane
transport
43
does not require
energy; substances exist in a
gradient and move from areas of higher concentration to areas of
lower concentration
passive transport
44
diffusion of water
osmosis
45
requires a
carrier
facilitated diffusion
46
the net movement of anything generally from a region of higher concentration to a region of lower concentration
diffusion
47
excess hypertonicity (water leaves the cell)
can cause damage to the cell and destroy it. cells shrivel and may die.
48
excess hypotonicity (water rushes into the cell)
can cause damage to the cell and destroy it, cell may burst and die
49
transporters of a single substance, either in or out
uniporters
50
transporters of two substances at the same time
symporters
51
transporters of two substances, but in opposite
antiporters
52
Materials repelled by the membrane enter the
cell with help of membrane proteins. Do not require energy input to function moves down the concentration gradient. These helper membrane proteins are
channel proteins or carrier proteins
53
requires energy
and carrier proteins; gradient
independent
active transport
54
involves the use of chemical
energy, such as ATP, to drive the transport.
primary active transport
55
utilizes energy from a
proton motive force (PMF).
secondary active transport
56
An ion (charged) gradient that develops when the
cell transports electrons/protons
proton gradient
57
Uses energy from an energy-rich organic compound that is not ATP. also modifies the substance being transported during the process.
group translocation
58
aids in the uptake of sugar (the glucose can’t be removed once it is phosphorylated)
the phosphotransferase system in bacteria
59
bringing substances into the cell through a vesicle or phagosome
endocytosis
60
ingests non specific substances or
cells
phagocytosis
61
ingests liquids and the solutes within
pinocytosis
62
True or False: Receptor Mediated is a specific type
true
63
is defined not in terms
of increases in cell size but in terms of
an increase in the total number of cells
which occurs by cell division (in bacteria
usually via binary fission)
microbial growth
64
Cell duplicates its components and divides into two daughter cells via a septum which grows
between them to separate them, In actively dividing cells, DNA synthesis is continuous (vs. euk
cell cycle) and the chromosome is replicated shortly before division, The chromosome attaches to
the cell membrane and as it
grows it pulls the two
chromosomes into the daughter cells,
Binary Fission
65
which phase of growth: not increasing in number, rather they are metabolically active. growing in size, making new enzymes, using nutrients from the medium, producing energy. Bacteria use this time to get acclimated to the new environment.
Lag phase
66
which phase of growth: after adjustment, the MO grow at a logarithmic rate. Generation time is the time interval it takes for the number of MOs to double in number.
Log phase
67
can logarithmic growth go on forever?
NO! Medium contains a fixed amount of nutrients, space, oxygen, etc. (limiting
factors to a population)
As the bacterial number increases, they use up the resources of the medium
and are expelling waste into the medium
As the nutrients are used up the cells cannot make as much ATP and growth
slows and levels of
68
which phase of growth: rates of cell division equals the rate at which old cells die. less new cell growth due to used up nutrient supply. Increased death due to toxic waste materials and changes in pH and oxygen availability.
stationary phase
69
as the environment becomes less supportive and more toxic, most cells die. Cell number decreases at a log rate. Cells can undergo involution or a change in shape. Nutrient limitation will drive spore forming MO to form spores and metabolically active vegetative cells will die. 100 percent cell death is unlikely.
death phase
70
how do you measure bacterial growth
estimate the number of cells resulting from binary fission during a set period of time. expressed in terms of viable cells/mL of culture: standard plate count, direct microscopic or automated counts, turbidity
71
a single, viable (living) bacterium will give rise to a single colony on an agar plate. usually necessary to dilute your bacterial sample so it is possible to count your colonies.
standard place count
72
each single, viable bacteria spread on the agar will divide to form a colony. plate different dilutions to obtain a plate with a countable number of colonies per plate. you would then multiply countable colonies by your dilution factor to figure out how many bacteria are in your initial sample.
serial dilutions
73
culture placed onto an etched glass slide and the microorganisms are manually counted using a microscope. culture can also be put into a machine that will automatically count cells.
direct microscopic count
74
the cloudy appearance of media when bacterial growth is present. the amount of light that passes through the culture can be measured using a spectrophotometer. degree of cloudiness, reflects the relative population size
turbidity
75
are these environmental factors affecting bacterial growth physical or nutritional: pH, temp, oxygen, moisture, hydrostatic pressure, osmotic pressure, radiation
physical factors
76
are these environmental factors affecting bacterial growth physical or nutritional: fastidious, carbon sources, nitrogen sources, sulfur and phosphorous, trace elements, vitamins
nutritional factors
77
organism must have a
certain environmental condition
obligate, Ex: obligate aerobe
78
organism can adjust to
and tolerate the environmental
condition, but it can also live in other conditions
facultative, Ex: facultative anaerobe
79
- the pH at which microorganism
grows best
optimum pH
80
Many MO produce acids (lactic acid, pyruvic acid)
that makes the area more acidic and slows
growth by acting on the cell membrane (without
environmental buffers)
Classification of bacteria according to their
tolerance of acidity or alkalinity
pH
81
pH (.1-5.4)
acidophiles
82
pH 5.4 - 8
neutrophiles (most disease causing MO)
83
pH 8-11.5
alkaliphiles
84
Preferred temperature is
determined by
when enzymes function best
85
Like temps around 15-20 C
Obligate (die at temps above 20C)
Facultative (grow best under 20C, but
can grow at higher temps as well)
psychrophiles
86
Like temps around 25-40 C
mesophiles
87
Like temps around 50-60 C
Obligate (cannot grow at temps lower
than 37C
Facultative (grows best at higher
temps)
thermophiles
88
are looking to become stable and will do so by stealing an e- from another
molecule damaging cell components
superoxide O2 and hydrogen peroxide H2O2
89
Most cells have developed enzymes that
neutralize these chemicals:
superoxide, dismutase, catalase
90
– utilizes oxygen and can detoxify it
aerobe
91
does not utilize oxygen (but can live with it around)
anaerobe
92
requires only a small
amount of oxygen
microaerophilic
93
grows best at higher CO2
concentration than normally present in the
atmosphere (like ~5-10%, only 0.04% in air)
capnophile
94
Pressure from
standing water
hydrostatic pressure
95
Bacteria able to
withstand high
pressure are
barophiles (they die at atmospheric pressure because their enzymes require the high pressure to maintain the correct conformation of their enzymes
96
Solutes in environment can affect
water content of bacteria
97
plasmolysis
lots of solute in environment
98
less solute in environment
turgidity
99
used as a curing agent to
prevent bacterial growth
salt
100
require moderate to
large amounts of salt for life – up
to 30%!
halophiles
101
do not require high
concentration of solute but can tolerate it when it occurs
osmotolerant
102
commensal member
benefits, other member neither harmed
nor benefited (+/0)
commensalism
103
parasite is dependent and
benefits; host is harmed (
parasitism
104
members cooperate to
produce a result that they could not
do alone
synergism
105
actions of one organism
affect the success or survival of others
in the same community (competition)
antagonism
106
result when organisms
attach to a substrate by some form of extracellular matrix that binds
them together in complex
organized layers
biofilms
107
what are the metabolic processes rules
cells need nutrients, require energy from light, energy is often stored in ATP, enzymes are needed for both catabolic and anabolic reactions, macromolecules are made, cells grow by assembling these macromolecules into cellular structures, cells divide in two once they have doubled in size.
108
sum of all the chemical processes carried out by living organisms
metabolism
109
synthesis of more complex molecules from simpler molecules. growth, reproduction, repair of damaged cellular structures. requires energy
anabolism
110
breaking down of complex molecules into simpler molecules. provides a source of energy used for movement, transport, and synthesis of complex molecules
catabolism
111
How is energy harvested/captured from the
breaking down of complex molecules?
– At a cellular level large molecules such as
glucose are broken down via many small steps
so energy can be captured and little is lost or
wasted
* This energy capture is in the form of
electron transfer…energy is stored in the
chemical bonds of ATP, NADH, and FADH2
* This energy is released when these bonds
are broken
112
The energy required for all reactions
to begin (exergonic AND endergonic)
[initial push to get out of bed in the
morning – then go through rest of the
day]
activation energy (E a)
113
higher Ea means
slower reaction rate
114
Where does Activation energy
come from?
heat energy from surroundings. heat increases molecule motion, causing higher chance of collisions of reactants.
115
provide a surface (active site) to bring
molecules (substrate) in the correct orientation
for the reaction to occur to create the product
enzymes
116
117
Place on the enzyme where substrate(s) are brought
together to create product(s). very specific to its substrate molecules
enzyme active site
118
– transported extracellularly, where they
break down large food molecules or harmful chemicals
exoenzymes
119
retained intracellularly and function
there
endoenzymes (most enzymes are endoenzymes)
120
protein
component of enzyme
apoenzyme
121
nonprotein,
organic molecule
loosely bound to
enzyme, brings helpful
pieces for reaction
coenzyme
122
inorganic ion
– Improve the fit of the
substrate and enzyme
– Minerals
cofactor
123
how does a cell stop enzymes from always pumping out product?
inhibition
124
Depends entirely on concentration of inhibitor in relation to concentration of substrate
* Reversible inhibition if inhibitor falls out of active site normal substrate can easily fit in
* Most inhibition is irreversible as the Enzyme is destroyed
competitive inhibition
125
Reversible, noncompetitive
* Seen in many metabolic pathways to avoid making
product the cell already has enough of so resources
can be shifted elsewhere to make a product the cell
feedback inhibition
126
* A build up of product on one side will
push the reaction towards the
substrates and vice versa
* Using up the product in a subsequent
reaction will drive the reaction towards
product
concentration
127
– Binds to enzymes that repair breaks in
peptidoglycan cell wall during cell growth
cell lysis
penicillin
128
– Disrupt an enzyme necessary for folic acid
synthesis (an important coenzyme for many
other enzymes)
– Without it, enzyme activity is halted and
growth is disrupted
– Humans are not affected by sulfa drugs
because we do not synthesize folic acid, rather
we must get it via diet
sulfa drugs
129
Metabolic “battery”
* Hydrolysis = breaking ATP ADP
* ATP utilization and replenishment is a constant cycle in active
cells
* ATP generation is the goal of metabolism!
Adenosine Triphosphate: ATP
130
ATP can be formed by three different
mechanisms:
substrate level phosphorylation, oxidative phosphorylation, photophosphorylation
131
Which mechanism of formation of ATP: – transfer of phosphate group from a phosphorylated compound (substrate) directly to ADP
substrate level phosphorylation
132
Which mechanism of formation of ATP: – series of redox
reactions occurring during respiratory pathway
generates about 90% of cell’s ATP
oxidative phosphorylation
133
Which mechanism of formation of ATP: – ATP is formed utilizing the
energy of sunlight and redox reactions
photophosphorylation
134
* Coenzyme, electron carrying molecule
* Carries e- to be used in fermentation or in
the electron transport chain (“electron
taxi”)
* NAD (oxidized form without an e-) is in
limited supply and must be available for
glycolysis to proceed
NAD +/ NADH
135
Second coenzyme and electron carrying
molecule (FADH2 Flavin adenine
dinucleotide) is used in the electron
transport chain
– FAD+ is oxidized form ; FADH2 is reduced form
(accepts 2 e- and 2 H)
FAD +/ FADH2
136
the loss or removal of electrons
corresponding to loss of energy
oxidation
137
gain of electrons corresponds
to gain of energy
reduction
138
what is it called when a reduction oxidation reaction happens together.
a REDOX reaction
139
a chain of chemical reactions
mediated by protein enzymes
– Anabolic builds up
– Catabolic breaks down
– The product of one set of chemical reactions is the
substrate for the next
metabolic pathway
140
Occurs in Cytoplasm of cells
* 10 step process mediated by enzymes to break down glucose (6 Carbon Sugar) into two molecules of pyruvate
* Used by autotrophic and heterotrophic organisms
– Autotrophs make their own glucose via
photosynthesis and then break it down while
heterotrophs get it from an outside source and then break it down.
* Does not require Oxygen but can happen in its presence (anaerobic process)
glycolysis
141
what happens during glycolysis?
A 6C-molecule (glucose) is broken down into two 3Cmolecules (pyruvate)
* ATP energy is used to start the reaction via substrate
level phosphorylation
* Transfer of 2 e- to the coenzyme NAD to produce
NADH
* Energy is captured in ATP
142
A phosphate group is transferred to
each end of the glucose molecule for
two reasons:
– Increases the energy of glucose to start
glycolysis (overcomes activation energy)
– This modification is a way of keeping
glucose from leaking back out of the cell
via glucose transporters
* Typically there is more glucose inside a cell
than outside (Remember diffusion?)
143
After glycolysis further metabolism
of pyruvate in the absence of oxygen
– No ATP but fermentation results in the removal of
e- from NADH freeing the NAD molecule to be
used again in glycolysis (recycle!)
* Many different pathways (Ex:
Homolactic acid fermentation and
alcoholic fermentation)
fermentation
144
Used by animals, fungi,
and some bacteria
Red blood cells, bacteria in
yogurt, muscle cells that
have run out of oxygen to
use. use to make cheese, yogurt, and buttermilk, pepperoni, pickles, sourdough, bread. Only 2 ATPs are produced.
lactic acid fermentation
145
Used by bacteria and yeast
* Again, only 2 ATPs are produced
* Pyruvate is reduced to make ethanol and releases CO2
* Process is used to make bread, beer, and wine
alcoholic fermentation
146
– Uses 2 ATP, yields 4 ATP (2 net ATP) and 2NADH
– In the presence of Oxygen the NADH will carry
the e- to the electron transport chain
– In the absence the NADH will be recycled to
NAD to replenish the supply and keep the
glycolysis wheel turning
glycolysis
147
– Does not yield any ATP but important for
recycling NADH (and the byproducts that are
released!)
fermentation
148
Where do the products of
glycolysis go?
* In the presence of oxygen, the Carbon
molecules go to the Doorway step to
prepare them for the Kreb’s Cycle.
* The NADH goes to the Electron Transport
Chain.
149
Occurs in cytoplasm of prokaryotes and
mitochondria matrix in eukaryotes
pyruvate transformation
150
* In cytoplasm of prokaryotes, or mitochondria matrix of
eukaryotes
* Further metabolizes glucose following glycolysis
* The Citric Acid Cycle (CAC), A.K.A. Kreb’s Cycle, A.K.A. TCA
cycle
Krebs cycle
151
which step in the krebs cycle: converts pyruvate to Acetyl-CoA
doorway/preparation step
152
which step in the krebs cycle: Acetyl groups are oxidized to carbon dioxide in 8 steps
oxidation of carbon
153
which step in the Krebs cycle: Hydrogen atoms are removed and their e- are
transferred to coenzymes NAD+ and FAD+ NADH
and FADH2
transfer of e- to coenzymes
154
which step in the krebs cycle: Addition of a phosphate (GDP + P = GTP) occurs
directly via a reaction of the Kreb’s cycle
* GTP is easily transferred to ATP so we can count
GTP as a gain of ATP
substrate level phosphorylation
155
the process leading
to the transfer of electrons from
substrate to final electron acceptor. Series of oxidation and reduction reactions
* Transfers e- from a level of higher energy to one of lower energy (cascade)
* Accepts e- from an e- donor and passes them to an e- acceptor
* Conserves energy from the e- transfer for ATP synthesis
Electron Transport Chain
156
How does the ETC make ATP
chemiosmosis- conversion of ADP + P to ATP via ATP synthase (an enzyme).
157
classified as an enzyme, a
motor, and an ion channel
* Protons enter at the intermembrane
space and cause the pump to spin which
causes ADP to be phosphorylated into ATP
* The ETC and ATP synthase are responsible
for 90% of aerobic ATP production
ATP synthase
158
what goes in for ETC
– 10 pairs of e- from NADH
– 2 pairs from FADH2
– 6 O2 (Aerobic respiration)
159
what goes out for ETC
– 34 ATP
– 6 H2O
160
where do metabolic reactions take place for glycolysis
prokaryote: cytoplasm, eukaryote: cytoplasm
161
where do the metabolic reactions for doorway to krebs cycle take place
prokaryote: cytoplasm, eukaryote: matrix mitochondria
162
where does the metabolic reaction for krebs cycle take place
prokaryote: cytoplasm, eukaryote: matrix mitochondria
163
where do the metabolic reaction for ETC take place
prokaryote: plasma membrane, eukaryote: inner membrane mitochondria
164
– Broken down by
beta oxidation (4
step process)
– Product is acetylCoA which then
feeds into Kreb’s
cycle
fat
165
Hydrolyzed into
amino acids
– Products vary and
can enter
glycolysis,
fermentation, or
the Kreb’s cycle
proteins
166
Relationship where two organisms live in close proximity, one benefits while the other may benefit, be harmed, or not be affected at all
symbiotic
167
completely assembled, functional enzyme
holoenzyme
168
changes shape of enzyme so it cannot bind to substrate
allosteric inhibitor
169
