Exam 3: Biology

Enzymes

-biological catalysts that speed up chemical reactions
-require activation energy
-only facilitates 1 type of reaction

Active Site

interacts with substrates; have chemical charges or not

Substrate

-a molecule that interacts with an enzyme
-physical and chemical properties have to be compatible with the active site

Allosteric site

region on enzyme where noncompetitive inhibitors can bind too

Competitive Inhibitor

-bind to active sites
-competes with normal substrates for active site
-binding can be irreversible: enzyme function prevented
-binding can be reversible: function is regained

Noncompetitive Inhibitor

-bind's to enzyme's allosteric site
-changes enzymes activity and shape: causes reaction rate to decrease

Product

-what is produced by the chemical reaction of an enzyme
-differs between each enzyme

Denaturing of an enzyme

- changes from environmental temperature or pH level change
-change from competitive and noncompetitive inhibitors

Temperature

increase of _________ outside of optimum range results in enzyme denaturation

pH Level

increase or decrease of _________ outside of optimum range results in denaturation

Photosynthesis

biological process that captures energy from the sun and produces sugars

6CO2 + 6H2O + Photons >>>> C6H12O6 +6O2

photosynthesis formula

Palisade Mesophyll

type of leaf cell that contains chloroplasts

Light Dependent Reaction

step 1 of photosynthesis

1. Photo Excitation

light photon strikes chlorophyll in PSII, which energizes the e- ; e- leaves

2. Electron Transport Chain

e- jumps down the ETC, losing energy as it goes. Some released energy moves hydrogen across the membrane from the stroma to the thylakoid. e- loses energy and tops in PSI

3. Electron Transport Chain

Photon Excitation occurs in PSI, which energizes the e-. The e- jumps down ETC and into the Stroma

4. Reduction NADP+ to NADPH

the e- that enters the stroma meets the NADP+ and changes it into NADPH

5. Photolysis

sunlight breaks down H2O. The H2 is added into the thylakoid. O2 is the byproduct and is released by the plant. e- is stripped from H and replaces the e- in PSII

6. Chemiosmosis

H+ gradient is established, ATP synthase will push H+ ions to reduce ADP to ATP

7. Reduction ADP to ATP

ATP synthase will use the power from H+ ion to reduce ADP to ATP

NADPH and ATP

molecules created for the Calvin Cycle

Hydrolysis Reaction

the hydrogen molecules from the splitting of water are released into the thylakoid space and are used to create H+ ion gradient

Location of Photosynthesis

in chloroplasts; light reactions occur in the thylakoid with the help of the stroma

Calvin Cycle

-Step 2 of Photosynthesis
-uses NADPH and ATP from the light dependent reaction

Rubisco

the enzyme used in the Calvin Cycle to bond CO2 and RuBP

1. Carbon Fixation

CO2 binds to RuBP sugar with the help of the Rubisco enzyme
- 6-carbon molecules split into 3-carbon molecules

2. Activation and Reduction

3-PGA is converted into G3P. ATP and NADPH are added
-ADP and NADP+ returns to the thylakoid

3. Replacement of RuBP

1 G3P is kept while 5 G3P are used to make RuBP with ATP

2 times

the Calvin Cycle must be repeated _ _____ in order to make 1 glucose

Stroma

location of the Calvin Cycle

Cellular Respiration

involves the capture of energy from macromolecules, which then releases chemical energy through the break-down of glucose and creates ATP

Anaerobic Respiration

Production of ATP when O2 is not present
-fermentation
-allows glycolysis to proceed in the absence of O2

Lactic Acid

byproduct of fermentation

Aerobic Respiration

the production of ATP
-occurs in the linking reaction, Krebs Cycle, and electron transport chain

Linking reaction

-requires O2
-occurs in the intermembrane of the mitochondria
-makes Acetyl CoA from pyruvates and NAD+

Krebs Cycle (Citric Acid Cycle)

-requires O2
-occurs in the matrix of mitochondria
-uses Acetyl CoA + NAD+ + FAD + ADP + to make NADH + FADH2 + ATP +CO2

Electron Transport Chain

-requires O2
-occurs in the inner mitochondrial membrane (matrix and inner membrane)
- uses NADH and FADH2 to energize electrons. The e- goes down the ETC, releasing hydrogens. Through Chemiosmosis, the hydrogens bond with O2 to form water and 36 ATP are created through ATP Synthase

ATP Hydrolysis

-the _________ of ATP molecules results in a net output of energy
-splitting bonds of ATP, creating energy for the cell