Studied by 3 peopleIn enzymes, kinetic energy is stored in the
bonds
A reaction starts with a ________ and ends with a _________.
substrate, product
Energy of activation
the amount of energy required to start a reaction
Enzyme
A type of (usually) protein that speeds up a chemical reaction in a living thing
enzymes are
organic catalysts
Characteristics of catalysts
speed up reactions by lowering activation energy, only work in one specific reaction, reusable
Substrate
A specific reactant acted upon by an enzyme
Active site
The part of an enzyme where the chemical reaction occurs.
induced fit model
enzyme model where the substrate induces the enzyme to alter its shape slightly so it fits better
Enzyme-substrate complex
A temporary complex formed when an enzyme binds to its substrate molecule(s).
After chemical reaction, substrate(s) turn to
Product(s)
Factors that can affect enzymes
temperature, pH, and enzyme concentration
Cold temperatures will make reactions
slower
Warm temperatures will make reactions
faster
If an enzyme gets too hot
it will denature
Denaturation
loss of normal shape of a protein due to heat or other factor
If an enzyme is exposed to pH levels that are too acidic or too basic
it will denature
The more enzyme in a reaction
the faster the reaction proceeds
The less enzyme in a reaction
the slower the reaction proceeds
the more substrate in a reaction
the slower the reaction proceeds with more product
The less substrate in a concentration
the faster the reaction proceeds with less product
Inhibitors
stop or slow the enzyme's functioning
Competitive inhibitors
Compete with the substrate to slow the enzyme's ability to function
Noncompetitive inhibitors
Bond with the enzyme and stop is functioning, potentially causing permanent damage to the enzyme
Examples of noncompetitive inhibitors
toxins and poisons
Negative feedback
When the body uses competitive inhibitors to regulate itself
Cofactors
inorganic enzyme helpers (ions and minerals)
Coenzymes
organic enzyme helpers (vitamins)
Exergonic reaction
when a reaction releases energy
Endergonic reaction
when a reaction takes in more energy than it releases (stores)
Electronegativity
tendency of atoms to want to take electrons from other atoms
Redox reactions
When there is a transfer of one or more electrons from one reactant to another (oxidation and reduction)
Oxidation
when an atom loses an electron during a reaction
Reduction
when an atom gains an electron during a reaction
Biochemical pathway
a series of linked reactions
Metabolism
the sum of the reactions in a biochemical pathway
Homeostasis
when a cell regulates its chemical reactions/maintains internal equilibrium
ATP (adenosine triphosphate)
transports energy needed for metabolic reactions around the cell
ATP is a
nucleotide, with ribose as its sugar and adenine as its nitrogenous base
ATP has ___ phosphate groups
three
ADP (adenosine diphosphate)
the outcome of ATP after the energy within is used
ATP has ___ and ADP has ___
energy, no energy
Photosynthesis uses the energy of what to make sugar
Sunlight
Autotrophs
organisms that preform photosynthesis
Photons
particles of light that move in waves
Sunlight is
visible/white light
Pigments
capture most of the plant's energy
Chlorophyll
Most common pigment, absorbs all colors except green
Chlorophyll A
Primary pigment, absorbs more red
Chlorophyll B
Accessory pigment, absorbs more blue
Carotenoids
absorb more blue and reflect orange
Formula for photosynthesis
6H₂O + 6CO₂ → C₆H₁₂O₆+ 6O₂
Chloroplast
Organelle that preforms photosynthesis
Thylakoid disk
membrane of the chloroplast folded up (inside the chloroplast), contain chlorophyll
Thylakoid membrane
membrane in which pigments are embedded
Granum
a stack of thylakoid disks (grana if plural) the unit that collects light
Light dependent reactions
set of reactions in photosynthesis that use energy from light to produce ATP and NADPH
Photosystems I and II
light-harvesting units of a chloroplast's thylakoid membrane
electron acceptor molecule
A reactant that gains an electron and is reduced in a reduction-oxidation reaction.
Electron transport chains
the series of molecules through which excited electrons are passed along a thylakoid membrane during light dependent reactions
NADP+
carrier molecule that transfers high-energy electrons and other molecules
NADPH
NADP+ carrying electrons and hydrogen (to the stroma for the Calvin Cycle during photosynthesis)
In order o make up for "lost" electrons and hydrogen in LDR
H2O is broken down into hydrogen ions, oxygen, and electrons, which is also how plants produce oxygen
Light Independent Reactions (Calvin Cycle)
use energy from the light dependent reactions to make sugars (happens in the stroma)
Rubisco enzyme
Splits the 6 carbons into 2 groups of 3 carbon molecules (PGA)
PGA
phosphoglycerate; a three-carbon molecule formed in the first step of the Calvin cycle
What is added to the Calvin Cycle that was produced during LDR?
ATP and NADPH, making ADP and NADP+ after their use in the Calvin Cycle
G3P
molecule that is made in the Calvin cycle; glucose is formed when two of these molecules combine
Some G3P are recycled to make
RuBP to start over the Calvin Cycle
RuBP
ribulose biphosphate; a five-carbon carbohydrate that combines with CO2 to form two molecules of PGA in the first step of the Calvin Cycle
During photosynthesis, carbon in CO2 becomes
carbon in C6H12O6
During photosynthesis, oxygen in CO2 becomes
oxygen in C6H12O6
During photosynthesis, hydrogen in H2O becomes
hydrogen in C6H12O6
During photosynthesis, oxygen in H2O becomes
oxygen in O2
Cellular Respiration
Process that produces ATP by breaking down food molecules (specifically glucose)
Formula for cellular respiration
C6H12O6 + O2 -> CO2 + H20
All organisms perform
cellular respiration (or at least some steps)
Heterotrophs
An organism that obtains its food by means of other organisms
Three parts of cellular respiration
glycolysis, citric acid cycle, electron transport chain
Anaerobic process
metabolic process that does not require oxygen
Glycolysis
an anaerobic process, the splitting of sugar that occurs in the cytoplasm (performed by all organisms)
Substrate-level phosphorylation
The formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.
Product of glycolysis
2 pyruvate
Net gain of ATP in glycolysis
2 ATP
Electron Carriers of Cellular Respiration
NAD+ and FAD
Aerobic process
a metabolic process that requires oxygen
citric acid cycle
an aerobic process, the oxidizing of acetyl Co-A (modified pyruvate) into CO2, occurs in the matrix of the mitochondria
Products of citric acid cycle
2 CO2, 1 ATP, 3 NADH, 1 FADH2
The Citric Acid Cycle takes ___ turns to make one glucose
two
Electron Transport Chain (ETC)
uses the high-energy electrons from the NADH and FADH2 from the Citric Acid Cycle and glycolysis to convert ADP into ATP, occurs in the cristae of the mitochondria
Oxygen is necessary to make
ATP
The oxygen we breathe becomes ___ at the end of the ETC
H2O
The carbon from the food we eat becomes___ at the end of the Citric Acid Cycle
CO2
Fermentation
Returns NADH to NAD+, which is necessary for glycolysis to occur
Anaerobic organisms must
perform glycolysis and fermentation to survive
strict anaerobes
Organisms that can't survive in an atmosphere of oxygen
Facultative anaerobes
Organisms that can survive with or without oxygen
Fermentation begins at the end of
glycolysis
Substrate for fermentation
pyruvate
Fermentation takes place in the
cytoplasm
Note
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