Exam 2 Flashcards
the capacity to do work
energy
how does position affect energy?
a higher position creates a higher potential energy because of gravity
What doest the first law of thermodynamics state?
Conservation of energy: amount of energy in a system remains constant
What does the second law of thermodynamics state?
When converted from one form to another, useful energy decreases. Because of this, entropy increases.
When energy is converted, what is it lost as?
heat
forming and breaking of bonds among atoms
chemical reactions
what type of reaction is the burning of glucose in mitochondria?
exergonic
what type of reaction is photosynthesis?
endergonic
What is required for the synthesis of ATP?
ADP + energy + inorganic Phosphate
What is released in the breakdown of ATP?
ADP+ energy + inorganic Phosphate
Explain a coupled reaction in a living cell.
Glucose breaks down to produce CO2, H2O, and heat. That exergonic reaction gives off energy to charge ATP synthesis which then breaks down to create ADP. ATP gives energy to amino acids to create a protein.
How do cells control their metabolic reactions?
limit production of ATP. Too much ATP slows down metabolic production of ATP and vice versa
sum of all of the chemical reactions in a cell
metabolism
How is metabolism controlled?
Enzymes regulate chemical reactions. Cells couple the reactions, and energy carriers capture carriers from exergonic reactions and deliver to endergonic reactions
What are the five properties of biological catalysts (enzymes)? 3 for all catalysts. 2 for only enzymes
- Speed up reactions
- Speed up reactions that would occur anyway
- Not consumed in reactions
- Enzymes are very specific
- Enzyme activity is regulated
What are the steps in enzyme-substrate interactions
- Substrates enter active site
- Shape change promotes reaction
- Product released; enzyme ready to start again
What are three types of enzyme regulation?
Feedback inhibition. Allosteric regulation. Competitive inhibition.
inhibits an enzyme in the metabolic pathway by stopping production of a product if too much already exists
Feedback inhibition
Explain allosteric regulation
inhibits the enzyme by changing the shape of the active site. The shape is changed by an allosteric regulator going into the allosteric regulation site.
Explain competitive inhibition
competitive inhibitor occupies the active site and blocks the substrate from going in there
What type of organisms use photosynthesis?
Plants, Bacteria, Protists (Algae)
What can occur if the stomata is open?
Water can leave and CO2 can get into the leaf
What can occur if the stomata is closed?
CO2 cannot enter the leaf which may result in no photosynthesis
microscopic opening in the epidermis of leaves that allow the exchange of gases between the outside air and the inside of the leaf
stomata
How do the stomata open?
Ions are actively put into the guard cells, and the water follows it by osmosis. Limp cells become turgid and open the stomata
How do the stomata close?
Ions are actively taken out of the guard cells and the water follows by osmosis. Turgid cells become limp and close the stomata
What factors control stomata opening and closing?
CO2 concentration and Humidity
How does CO2 concentration control the stomata?
when the concentration in the leaf falls the guard cells become turgid and open the stomata
How does humidity control the stomata?
Stomata close on hot, dry, windy days. At dawn a sudden increase in stomata opening, reaching a max near noon, is followed by a decline because of water loss.
How does water leave the turgid guard cells?
aquaporin channel
cells inside the leaf
mesophyll cells
What do veins inside of the leaf transport?
Sugars
What are the components of the chloroplast?
inner and outer membranes, stroma, thylakoids, granum, circular DNA
What are the two main parts of photosynthesis and where do they occur?
Light Dependent (thylakoids) and Light InDependent (stroma)
What happens in the Light Dependent reactions?
Depleted carriers (ADP, NADP+) react with light and H2O to become energized carriers (ATP, NADPH) and give off oxygen as a byproduct
What happens in the Light Independent reactions?
Energized carriers (ATP, NADPH) react with CO2 and H2O to become depleted carriers (ADP, NADP+) and give off glucose as a byproduct
What are the three photosynthetic pigments?
Chlorophyl, Carotenoids, Phycocyanins
How does chlorophyll acquire its pigment?
Absorbs violet, blue, and red. Reflects Green
How do carotenoids acquire their pigments?
Absorb blue and green. Reflect yellow, orange, and red.