Biology
Study Guide Chapters 4 (68-75) - 6
Study Guide Chapters 4 (68-75) - 6
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Flashcards
What's the difference between potential energy and kinetic energy?
stored energy vs. energy being used to do work
potential energy has the ability to cause change because of location or structure
kinetic energy is energy in motion
What is the first law of thermodynamics?
law of energy conversion
energy cannot be created or destroyed
energy can be converted to other forms
total amount of energy in the universe is constant
Does the first law of thermodynamics apply to living things?
yes
What is the second law of thermodynamics?
all energy transformations are inefficient
every eraction loses some energy as heat
process is irreversible
entropy
What is entropy
measure of randomness
how much energy has been dispersed or disorder is in the system
What is an example of how the second law of thermodynamics applies to living things?
Cellular respiration converting food energy to heat energy
Does an endergonic reaction require an input of energy?
yes
Do the products of an endergonic reaction have more or less energy than the reactants
more
What is an example of an endergonic reaction in living things?
photosynthesis
In an exergonic reaction, do the products have more or less energy than the reactants
less
What is an example of an exergonic reaction in living things?
cellular respiration
Are endergonic reactions spontaneous?
no
Are exergonic reactions spontaneous?
yes
What is activation energy?
the initial input of energy in a chemical reaction
What is the function of an enzyme?
speeds up a chemical reaction without being consumed
Is an enzyme a protein, carb, lipid or nucleic acid?
protein
How do enzymes work?
Substrate molecules bind to the enzyme's active site (where the chemical reaction occurs)
-once the chemical reaction occurs, product molecules are released (enzyme retains original form)
What are biochemical pathways?
the long chains of chemical reactions that take place in the normal operation of living systems
What does the activation energy do?
initiates a chemical reaciton by destabilizing existing chemical bonds
How are enzymes involved in biochemical pathways?
enzymes lower the activation energy (the energy required to start the reaction)
If a biochemical pathway has 10 steps, how many enzymes are involved in it?
9
What suffix tells you that a word is the name of an enzyme?
ase
What is a denatured enzyme?
the change in the 3 dimensional structure of an enzyme
Does a denatured enzyme still function?
no
Why doesn't a denatured enzyme still function?
the holes in the membrane channel are closed or the long, straight regions of the muscle proteins are bent
Do enzymes operate best at certain temperatures and pH levels or can they operate at any temperature and pH level?
enzymes are very sensitive to conditions in the cell
enzyme action speeds up as the temp climbs bc reactants have more kinetic energy at higher temps
What happens to an enzyme if you take it out of it's comfort zone?
the enzyme becomes denatured
What are the common types of enzymes?
hydrolases
nucleases
proteases
synthases
isomerases
polymerases
kinases
phosphatases
ATP-ases
oxidorectases (dehydrogenases)
What are the parts of ATP?
nitrogen-containing base adenine
five-carbon sugar ribose
and three phosphate groups (PO4)
How does ATP work?
the cell removes endmost phosphate group (product = ADP, the released phophate group, and a burst of energy)
Which has more energy, ADP or ATP?
ATP
Where does the photosynthesis happen?
chloroplasts
Identify the folowing parts of a chloroplast and say what stage of photosynthesis happens there: stroma, thylakoid membrane, grana
stroma - gelatinous with enzymes, ribosomes, DNA, and grana - carbon reactions
grana - stack of thylakoids - light reactions
thylakoid - membrane studded with photosynthetic pigments enclosing thylakoid space - light reaction
What pigment molecule is embedded in the thylakoid membrane?
chlorophyll
What is the function of chlorophyll?
harnesses the energy in sunlight
What are the reactants in photosynthesis?
CO2 / H2O and sunlight
What are the products of photosynthesis?
O2 / Glucose / ATP
What happens to the carbon dioxide that enters the plant?
CO2 becomes glucose
What happens to the water that enters the plant?
becomes O2
What are the wavelengths of the electromagnetic spectrum (the energy from the sun) that are used in photosynthesis?
Photons
