Unit 3 - Cellular Energetics Flashcards
What are biological catalysts that speed up biochemical reactions?
enzymes
Enzymes are ___________.
macromolecules
Substrates have a unique ______ and _______.
size, shape
Most enzymes are __________.
proteins
______ _______ must be maintained for an enzyme’s functionality
Tertiary shape
Enzymes have a region called an ________ _______.
active site
What is a molecule that can interact with an enzyme?
substrate
An enzyme’s active site SPECIFICALLY interacts with __________.
substrates
Substrates can have chemical ______ or not.
charges
Physical/chemical properties of the substrate MUST BE _______ with the enzyme’s ACTIVE SITE for a reaction to occur.
compatible
________ changes can occur to align with substrate
Slight
Enzyme names often indicate the ________ or chemical ______ involved.
substrate, reaction
Enzyme names often end in _____.
-ase
Enzymes are _________.
REUSABLE
Enzymes are NOT CHEMICALLY _________ by the reaction.
CHANGED
Enzymes are ________.
REUSABLE
Cells typically contain a _________ enzyme __________.
SPECIFIC, concentration
Enzymes can facilitate ________ or ________ reactions
synthesis, digestion (hydrolysis)
Enzymes speed up biochemical reactions by __________ activation energy requirements.
LOWERING
Enzymes are ________ catalysts, typically _______, that _____ up biochemical reactions.
biological, proteins, speed
Enzyme structure is very _______ resulting in each enzyme on facilitating ______ type of reaction.
specific, ONE
What is the initial starting energy for a reaction called?
Activation energy
Reactions result in a net _________ of energy or a net _________ of energy.
release, absorption
Typically, reactions involving a net RELEASE of energy require ______ activation energy compared to reactions involving a net ABSORPTION of energy.
LESS
Enzymes _______ the activation energy requirement of all enzyme-mediated reactions, ________ the rate of reactions.
LOWER, accelerating
In an enzyme SYNTHESIS reaction, what is the product?
Synthesized substrate
In an enzyme DIGESTION reaction, what is the product?
Hydrolyzed substrate = substrate separation and production of water molecule(s)
__________ procedures should ALIGN with the _________ question.
Experimental, TESTABLE
A controlled experiment is a scientific _________.
investigation
What are the two types of test set up in a controlled experiment?
- Control test (group)
- Experimental test (group)
A control test:
generates data under conditions with no ________/ no _________.
treatment, manipulation
A control test:
generates data under ________/_______ conditions.
normal, unchanged
A control test:
is considered __________ data
BASELINE
An experimental test:
generates data under ________/ _________ conditions.
abnormal, unknown
An experimental test:
generates data under ________/ _________ conditions.
treated, manipulated
An experimental test’s:
results are often _______ with control test results to help ________ possible ______ of a treatment/manipulation.
compared, determine, impacts
A control group is used as a standard for __________.
COMPARISON
What type of control is:
NOT exposed to experimental treatment
+
NOT exposed to any treatment known to have an effect
negative control
What type of control is:
NOT exposed to experimental treatment
+
EXPOSED to a treatment that has a known effect
Positive control
______ types of controls can be used to ________ experimental procedures.
BOTH, VALIDATE
A control group is NOT the same as a controlled ______.
variable
What are aspects of an experiment that could be changed but are intentionally NOT changed?
controlled variables
Controlled variables are:
important to help ______ and _____ the impact of an intentional change/treatment.
isolate, identify
Only variables known to have an _______ should be considered as possible controlled variables.
IMPACT
What is another name for controlled variables?
CONSTANTS
The control group is exposed to a treatment that has a ________ effect.*
KNOWN
Positive control groups confirm a ______ effect.
KNOWN
Negative control groups confirm results in the _______ of any kind of treatment.
ABSENCE
Energy stored in food is expressed in units called
Calories (CAPTIAL C)
The amount of energy needed to raise temperature of 1g of H2O by 1 degree Celsius
calorie (LOWERCASE C)
1000 calories = 1 _____calorie (_cal)
kilo, k
1 kcal = 1 _____ Calorie (BIG C)
FOOD
Chemists measure energy (enthalpy and Gibbs Free Engergy) in _______, and ENTROPY in ________.
kJ·mol−1, JK-1mol-1
Energy is released or put in depending on if a chemical reaction is _________ or ______ bonds. This all involves ________ _______.
breaking, making, moving electrons
What type of pathway breaks down complex molecules to simpler ones?
catabolic (EXergonic)
What type of pathway builds complex molecules?
anabolic (ENDergonic)
What does the -cata in “catabolic” mean?
degrade
What does the ana- in “anabolic” mean?
build
What is an example of a catabolic pathway?
digestion of food
What is an example of an anabolic pathway?
building muscle after exercise
Energy is the ability to do _______.
work
What is the energy of motion/movement?
kinetic energy
What is stored energy?
potential energy
What is potential energy stored in the bonds between atoms?
chemical energy
1st Law of Thermodynamics
Energy cannot be destroyed, it can only be transferred
2nd Law of Thermodynamics
From order to disorder; an increase in entropy is an increase in disorder
What is the main purpose of enzymes?
(Hint: To ______, by _____, which is _____)
- To speed up chemical reactions
- By lowering the activation energy,
- Which is the amount of energy needed for a reaction to occur
Enzymes are _____, so their shape is linked to the order of ____ _____ put together.
PROTEINS, amino acids
Substrates ________ by enzymes to form a new _____.
rearranged, product
What is an analogy for normal binding?
“One lock for one key, that opens the house”
lock = enzyme
key = substrate
opens = produces
house = product
Competitive inhibition involves:
- _________ between enzymes for _______ ________.
- __________________
- occurs with an ______ of substrate
- Competition, active site
- NO BINDING
- overflow
What are changes in the confirmational shape of an enzyme called?
denaturation
What changes can lead to environmental denaturation?
changes in pH and temperature
Enzyme denaturation is typically _______________, and the catalytic ability of enzyme is _____ or severely __________.
irreversible, lost, decreased
In some cases, enzyme denaturation is ________, allow the enzyme to _________ _______ ______.
reversible, regain catalytic activity
What is the range in which enzyme-mediated reactions occur the fastest?
optimum temperatures
Reaction rates _______ when optimum temperatures aren’t maintained.
change
Environmental increase in temp =
increased speed of molecular movement
frequency of enzyme-substrate collisions
Temp increase outside of optimum range =
Enzyme Denaturation
Environmental decrease in temperature =
It ________ ______ enzyme structure, SO what about denaturation?
slow down reaction rate
decrease frequency of enzyme-substrate collisions
doesn’t disrupt, no denaturation
What measures the concentration of hydrogen ions in solution and measured on a logarithmic scale?
pH
Small changes in ph values =
large shifts in hydrogen ion concentration
ph6 = 10x[H+] than ph7
What is the range in which enzyme-mediated reaction occur the fastest?
optimum pH
Changing pH ________ of optimum range will _____ or _______ enzyme activity
outside, slow, stop
Enzyme denaturation can occur as result of increases and decreases _______ ___ _______.
outside of optimum
Changes in [H+] concentration can disrupt ______ ______ that help maintain enzyme structure.
h-bond interactions
Initial increases in substrate concentration ______ reaction rate.
INCREASE
More substrates =
more opportunity to collide with enzyme
Substrate saturation =
no further increase in rate
If saturation levels maintained =
constant rate
Increased concentration of products =
DECREASE opportunity for addition of substrate
Matter takes up space
More product in an area =
lower chance of enzyme-substrate collisions = SLOW REACTION RATE
LESS enzyme =
slower reaction rate
LESS opportunity for substrates to collide with active sites
MORE enzyme =
faster reaction rate
**MORE opportunity for substrates to collide with active sites
What are molecules that can bind reversibly or irreversibly to the active site of the enzyme?
competitive inhibitors
Inhibitor concentrations EXCEED substrate concentrations =
SLOWED reaction rate
Inhibitor concentrations MUCH LOWER than substrate concentrations =
NORMAL reaction rate
If inhibitor binding IRREVERSIBLE =
enzyme function PREVENTED
If inhibitor binding REVERSIBLE =
enzyme can REGAIN FUNC one inhibitor detaches
______ _______ compete with the normal substrate for the enzymes active site.
Competitive inhibitors
What are enzymatic regions other than the active site to which molecules can bind?
allosteric sites
Noncompetitive inhibitors DO NOT:
bind to the active site
Noncompetitive inhibitors DO:
bind to ALLOSTERIC site
Binding causes what to change?
conformational shape
Binding prevents _______ function because the ______ ____ is ___ longer __________.
enzyme, active site, no, available
Increasing substrate CANNOT:
PREVENT effects of NONCOMPETITIVE INHIBITOR BINDING
All living systems require:
CONSTANT input of energy
What is the main energy input for living systems?
Sunlight
What captures energy from physical sources, like sunlight, or chemical sources and transform that energy in energy sources usable by all cells?
Autotrophs
During every energy transformation process some energy is ________, often ______ __ _______.
unsusable, lost as heat
Life requires a _________ ________ _____.
highly ordered system
Life DOES NOT:
violate the second law of thermodynamics
Every ENERGY TRANSFER INCREASES what?
DISORDER of the universerve
Living cells are NOT at _________. Why?
equilibrium. There is a constant flow of materials in and out of the cell.
How do cells manage energy resources?
energy-coupling
Energy-RELEASING processes drive energy-________ processes.
STORING
Pathways in biological systems are _________.
sequential
Within a chemical pathway, the _______ of one reaction can serve as a _______ in a subsequent reaction.
product, reactant
Sequential reaction allow for a more _________ and _________ transfer of energy.
controlled, efficient
What do chlorophylls do?
capture energy from sunlight and convert it to high-energy electrons
What happens to chlorophyll electrons when light absorption occurs, and what is the importance of this?
PART 1:
Electrons will be ________.
energized.
What happens to chlorophyll electrons when light absorption occurs, and what is the importance of this?
PART 2:
The energy from the electrons will be used to establish a _______ _____ and reduce _____ and _______.
proton gradient, NADP+ and NADPH
light-capturing unit in a chloroplast’s thylakoid membrane
photosystem
Why is the hydrolysis of water necessary as it relates to PSII and the light-dependent reactions?
The __________ molecules from the splitting of the water are:
- released into the ________ space
- used to create an ___________/________ __________.
hydrogen, thylakoid, electrochemical/proton gradient
PSII and PSI pass _______ _________ to the ETC.
high-energy electrons
To generate ATP from ADP, photosynthesis uses a form of _______ _____.
passive transport
