Chapter 3 Flashcards
Energy & Chemical Reactions
energy is
the capacity to do work
why are energy and matter different?
energy does not have mass and does not take up space
two forms of energy
potential and kinetic
potential energy is
energy that is stored/the energy of position
kinetic energy is
the energy of motion
what is an example of potential energy in the body?
concentration gradient between the inside and outside of the cell
four examples of kinetic energy
electrical
mechanical
sound
radiant
heat is
the kinetic energy associaed with random motion of atoms, ions, or molecules
heat is considered a
waste product
heat is measured as
temperature of a substance
chemical energy is
a form of potential energy where energy is stored in the bonds of a molecule
three main molecules involved in chemical energy storage
triglycerides
glucose
ATP
a chemical reaction occurs
when chemical bonds in an existing molecule are broken and new bonds are formed
metabolism is
a collective term for all biochemical reactions that occur in living organisms
a chemical equation is
the written summary of changes when a chemical reaction occurs
chemical equations are composed of
products and reactants
reactants are
present prior to the start of a chemical reaction and are the substances/substrates that are being reacted
products are
the substances that are formed from the reactants in the chemical reaction
decomposition reaction is where
one larger molecule is broken down into two or more smaller molecules
synthesis reaction is where
two or more atoms/molecules are combined to create a larger molecule
an exchange reaction is where
atoms/molecules are exchanged between two chemical structures
an exergonic reaction occurs when
the reactants at the beginning of the reaction have more potential energy than the products formed
in an exergonic reaction, heat is
released as a result of more potential energy in the reactants
an endergonic reaction occurs when
the reactants have less potential energy than the products
in an endergonic reaction, heat is
absorbed
ATP cycling is
the continuous formation and breakdown of ATP
ADP + P is (ender/exergonic)?
endergonic
ATP broken down to ADP + P is (ender/exergonic)?
exergonic
why is ATP production continous?
cells cannot store ATP
An irreversible reaction involves
reactants that are converted into products where there is a net loss of reactants and net gain products
A reversible reaction involves
reactants that are converted into products until an equilibrium is reached, a state where reactants to products and products to reactants is equal
A reaction at equilibrium will
stay until the concentration of either reactants or products is change
example of a reversible reaction
bicarbonate buffer reaction
reaction rate is
the measure of how quickly a chemical reaction takes place, determining the amount of product formed per unit time
Activation energy, Ea, is
the energy required to break chemical bonds so a reaction can proceed, the primary factor that influences the reaction rate
common way to provide energy to a reaction to overcome activation energy?
addition of heat
How does the body proceed in many chemical reactions?
catalysts, specifically enzymes
what happens when you add a catalyst to a reaction that does not necessarily need one?
the reaction rate can speed up, creating more products per unit time
what is the catalytic enzyme of the bicarbonate buffer?
carbonic anhydrase
most enzymes are
globular proteins
amino acids in the protein chain fold to form a unique, tertiary structure with a depression/grooved region called the
active site
An enzyme’s active site temporarily binds with the substrate of the reaction to form the
enzyme-substrate complex
can active sites bind to multiple different types of molecules?
no. active sites have a specific shape, only allowing a certain substrate or group of substrates to bind
three locations an enzyme may end up
remain in the cell
become embedded in the plasma membrane
be secreted from the cell and go elsewhere in the body
six main groups of enzymes
oxidoreductase
transferase
hydrolase
isomerase
ligase
lyase
oxidoreductases
transfer electrons from one substance to another
transferases
transfer functional groups
hydrolases
split chemical bonds using water
isomerases
convert one isomer to another
ligases
bond two molecules together
lyases
split chemical bonds in the absence of water
enzyme saturation is where
the concentration of a substrate is more than the enzyme can bind with
three environmental factors that can affect enzyme function
saturation
pH
temperature
cellular respiration is
multi-step metabolic pathway where organic molecules are broken down by various enzymes
four key characteristics of cellular respiration
Its processes are exergonic
The organic molecule that is being broken down releases high-energy electrons. When this occurs, the molecule is considered oxidized
Synthesis of ATP is an endergonic process
Oxygen is required for maximum ATP production
primary organic molecule used in cellular respiration
glucose
general chemical formula of cellular respiration using glucose
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
One glucose molecule + 6 oxygen molecules produces 6 carbon dioxide molecules + 6 water molecules
Cellular respiration occurs in two primary locations within the cell:
the cytosol and the mitochondria
four stages of cellular respiration
glycolysis
intermediate stage
citric acid cycle/krebs cycle/TCA
electron transport chain
glycolysis occurs in the
cytosol
the intermediate stage, citric acid cycle, and ETC occur in the
mitochondria
does glycolysis require oxygen?
no, it can occur anaerobically and aerobically
during glycolysis, glucose is broken down into _____ and produces ______
2 molecules of pyruvate
2 net ATP and 2 NADH
glycolysis has ___ enzymatically regulated chemical reactions
10
if glycolysis occurs anaerobically, the pyruvate is
further converted into lactice acid
the intermediate stage is catalyzed by
pyruvate dehydrogenase
the role of pyruvate dehydrogenase is to
bring together the newly formed pyruvate from glycolysis and CoA (coenzyme A) to form acetyl-CoA
decarboxylation occurs in the intermediate stage when
the carboxyl group from pyruvate is released as carbon dioxide
the intermediate stage forms
2 molecules of acetyl CoA
the citric acid cycle is catalyzed by _____ enzymes
nine
in the citric acid cycle, acetyl CoA is
sent into the cycle and converted into various molecules with the production of CO2, NADH, FADH2, and ATP
the citric acid cycle is regenerative, meaning
the products of each step are reused in the cycle to continue making these four products
five main structures of the ETC
four proton pump complexes
ATP synthase
the ETC works by
oxidizing products from the citric acid cycle and using the electrons as energy to send H+ (protons) up through the pumps into the intermembrane space of the mitochondria.
The concentration of protons in this space will increase and become greater than the mitochondrial matrix, sending protons through the ATP synthase, creating ATP from ADP and P
oxidative phosphorylation is
the process of producing ATP using the electron transport chain
oxidative phosphorlyation produces
32 ATP
10 NAD+
2 FAD
6 H2O
the citric acid cycle produces
4 CO2
6 NADH
2 FADH
2 ATP
the intermediate cycle produces
2 acetyl CoA
2 NADH
2 CO2
