Transcript METABOLIC PATHWAYS & ENZYMES

Metabolism – the Dynamic Cell
Spring 2013 - Althoff Reference: Mader & Windelspecht Ch. 6)
Lec
06
• Energy
• ATP: Energy for
Cells
• Metabolic Pathways
& Enzymes
• Oxidation-Reduction
What is Energy?
= the __________________, quantified by…
_______ = amount of heat required to raise the
temperature of 1g of water 10C
Potential Energy
Kinetic Energy
• ___________ energy
• Energy of ____________
• Constantly converted to • Constantly converted to
kinetic energy
potential energy
Successful organisms “_____” the energy game
__________ LAWS
• FIRST LAW OF THERMODYNAMICS (LAW OF
CONSERVATION OF ENERGY) Energy cannot be
created or destroyed, but it can be changed
from one form to another
• SECOND LAW OF THERMODYANMICS Energy
cannot be changed from one form to another
without a loss of usable energy.
Also associated with the term __________
--the relative amount of
disorganization associated with
every energy transformation
MORE organized
LESS organized
GLUCOSE
CARBON DIOXIDE
& WATER
LESS Entropy
• Less ___________
• More potential energy
• More organized
MORE Entropy
• More ____________
• Less potential energy
• Less organized
_____: what cells spend for
energy
• 1 adenosine
group
• 3 phosphate
groups
(triphosphate)
CHLOROPLAST
Flow of
Energy
MITOCHONDRION
CHEMICAL WORK
TRANSPORT WORK
MECHANICAL WORK
Functions of ATP…
• ______________ WORK —ex: protein, lipid,
carbohydrate synthesis or breakdown of those
complex organic molecules
• ______________ WORK —ex: move molecules
from one location to another, especially across
the plasma membrane
• ______________ WORK —ex: muscle
contractions, cilia and flagella to beat,
chromosomes to be moved
__________________ = all of the chemical
reactions that occur in a cell during growth and
repair
Metabolic Reactions
• _____________ REACTIONS —ENERGY REQUIRED,
RESULTS IN _______________ OF COMPOUNDS
• _____________ REACTIONS —ENERGY REQUIRED,
RESULTS IN _______________ OF COMPOUNDS
(chemical bonds are broken)
METABOLIC __________ = series of linked reactions
that begin with a particular reactant (i.e. SUBSTRATE) and
terminate with an end product
____________ = protein molecule that functions as a
catalyst in a chemical reaction (i.e, metabolic pathways)
• Enzymes ____________ these reactions
• Enzymes only speed up reactions, they
______________ make reactions that are not
possible to begin with
• Enzymes can “bring together” molecules that
will react to each other AND reduce the
___________________
• Enzymes can be “_____________”
METABOLIC PATHWAYS & ENZYMES
• A metabolic pathway can be represented by a
simple diagram.
E1
E2
E3
E4
E5
E6
A  B  C  D  E  F  G
– The letters A-G indicate ________________
– The letters E1-E6 represent _______________.
– A is the substrate for E1, B is the substrate for E2,
and so on.
Potential energy
More energy needed for
activiation
________________
ENZYME
Less energy needed for
activiation WITH ENZYME
REACTANT
PRODUCT
Reaction
Rate of Reaction
(product per unit of time
What affects
enzymes?
Temperature 0C
Rate of Reaction
(product per unit of time)
What effects
enzymes?
pH
1
Substrate
(reactants)
Enzyme
2
Reaction occurs
Products
3
Enzyme
 Reactants “_________________” on the enzyme
Reaction occurs ____________ because of enzyme
 Product results and enzyme is ‘______________’
Say it with “…______”: NAMING OF ENZYMES
Substrate/Reactant
• Lipid
• Urea
• Maltose
• Lactose
• Sucrose
• Ribonucleic acid
• some proteins
• some proteins
• Etc.
Enzyme
Lipase
Urease
Maltoase
Lactase
Sucrase
Ribonuclease
Trypsin
Pepsin
Oxidation & Reduction
• OXIDATION – _______ of electron(s) by
molecules during the oxidation-reduction
process
• REDUCTION –_______ of electron(s) by
molecules during oxidation-reduction process
• Both processes all take place at the same time
• Take place during photosynthesis and cellular
respiration
For the record…
• PHOTOSYNTHESIS is the _________ of CELLULAR
RESPIRATION
6CO2 + 6H20 + ENERGY  C6H1206 +6O2
PHOTOSYNTHESIS: H2O is oxidized, CO2 is reduced
C6H1206 +6O2  6CO2 + 6H20 + ENERGY
CELLULAR RESPIRATION:
C6H12O6 is oxidized, O2 is reduced
________________ – moving H+
• The production of ATP due to a hydrogen ion
(H+) ___________ across a membrane
• Occurs in _________________ and
_________________…the energy organelles
of cells
Starts with H+ pump pumping H+ _______ the
membrane
Completes when H + ions cross back through
the membrane through an
________________ complex
Mader, p115 – summary, Fig. 6.13
Chemiosmosis – moving H+
High H+ conc.
2
Low H+ conc.
1