FINAL TERM- PPT-BR Flashcards
What are enzymes?
Enzymes are proteins
How do enzyme works?
Enzymes catalyze
reactions by
weakening
chemical bonds,
which lowers
activation
energy.
Each enzyme has a unique 3-D shape, including a surface groove called
Active site
When an enzyme is interacting with it’s substrate, during the chemical reaction, together they are referred to as the
Enzyme-Substrate Complex
Enzymes have names that
usually end in __________
-ase
Formats for writing an enzymatic reaction
(__________)
_______ + ________ ———–> _________
(\_\_\_\_\_\_\_\_\_) \_\_\_\_\_\_\_\_\_\_ -----------> \_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_
(enzyme)
Reactant + Reactant ———–> product
( enzyme ) Reactant -----------> product product
How do you sabotage an enzyme?
Denature it
Factors that influence enzyme activity
- temperature
- pH
- Cofactors and Coenzymes
- Inhibitors
Most enzymes work best near _________
Neutral pH (6 to 8)
Non-protein portion of the
enzyme (ex. zinc, iron, copper,
vitamins) that is need for
proper enzymatic activity.
Cofactors/ Coenzymes
Most ___________ are
coenzymes essential in
helping move atoms between
molecules in the formation of
carbohydrates, fats, and
proteins.
Vitamins
Two types of enzyme inhibitors
Competitive inhibitor and Non-competitive inhibitor
Chemicals that
resemble an
enzyme’s normal
substrate and
compete with it for
the active site.
Reversible depending on
concentration of
inhibitor and
substrate.
Competitive inhibitor
- Do not enter active site, but bind to another part of the enzyme, causing the enzyme & active site to change shape.
- Usually reversible, depending on concentration of inhibitor & substrate.
Non-competitive inhibitor
Enzyme inhibitors are
also used as ___________
and ___________.
herbicides, pesticides
Sum of all chemical reactions in a cell
or organism.
Cells either get their energy either by
photosynthesis or by eating stuff.
Metabolism
Why are enzymes so important?
Nearly all chemical
reactions in biological
cells need enzymes to
make the reaction
occur fast enough to
support life.
The main form of energy from the sun is in the form of ________________
Electromagnetic radiation
Why are plants green?
Plants are green because the green wavelength is reflected, not absorbed.
is a pigment that absorbs red & blue light (photons) so green is reflected or transmitted.
Chlorophyll
2 Types of Chlorophyll
Chlorophyll a, Chlorophyll b
– Type of chlorophyll that is involved in light reactions
Chlorophyll a
Type of Chlorophyll that assists in capturing light energy – accessory
pigment
Chlorophyll b
accessory pigments – captures more light
energy
Carotenoids
During the fall, what causes the leaves to change colors?
- During the fall, the green chlorophyll pigments
are greatly reduced revealing the other
pigments - Carotenoids are pigments that are either red,
orange, or yellow
Photosynthesis are used by autotrophs such as:
- Plants
- Algae
- Some bacteria (prokaryotes)
energy-rich chemical produced through
photosynthesis
Glucose
series of reactions where the product of one reaction is consumed in the next
Biochemical pathway
The loss of electrons from a
substance or the gain of oxygen.
Oxidation reaction
The gain of electrons to a
substance or the loss of oxygen.
Reduction of electrons
Where does photosynthesis take place?
Mainly occurs in the leaves:
a. stoma - pores
b. mesophyll cells
Pores in a plant’s cuticle through which water vapor and gases (CO2 & O2) are exchanged between the plant and the atmosphere.
- found on the underside of leaves
Stomata (Stoma)
Organelle where photosynthesis takes place.
Chloroplast
What do cells use for energy?
Sunlight
It is composed of the nitrogen base ADENINE, the pentose (5C) sugar RIBOSE, and three PHOSPHATE groups
Adenosine triphosphate
FREE PHOSPHATE can be re-attached to
ADP reforming ATP, process called
Phosphorylation
Produces energy from solar power (photons) in the form of ATP and NADPH.
Light reaction
Also called Carbon Fixation or Carbon Cycle, Uses energy (ATP and NADPH) from light reaction to make sugar (glucose).
Calvin cycle
2 possible routes for electron flow:
Use Photosystem I and Electron Transport Chain (ETC) and generate ATP only OR use Photosystem II and Photosystem I with
ETC and generate O2 , ATP and NADPH
–PHOTO-CHEMICAL SPLITTING OF WATER
(RESTORING PHOTOSYSTEM II)
Photolysis
SYNTHESIS OF ATP
Chemiosmosis
carbon atoms from CO2 are
bonded or ‘fixed’ into carbohydrates
Carbon fixation
To produce glucose: it takes __ turns and uses __ ATP and __ NADPH.
6, 18, 12
use Calvin cycle exclusively
Form 3-carbon compounds
C3 plants
evolved in hot, dry climate
Form 4-carbon compounds
Partially close stomata
E.g. Corn, sugar cane, crabgrass
C4 pathway
open stomata at night, close in day
Grow slow, lose less water
E.g. cactus, pineapple
CAM
Hot, moist environments
15% of plants (grasses, corn,
sugarcane)
Photosynthesis occurs in 2 places:
Light reaction - mesophyll cells
Calvin cycle - bundle sheath cells
C4 plants
Hot, dry environments
5% of plants (cactus and ice plants)
Stomates closed during day
Stomates open during the night
Light reaction - occurs during the day
Calvin Cycle - occurs when CO2 is present
CAM plants
Electrons excite in _____________– move along ETC to _______________
Photosystem II, Photosystem I
