Bio Unit 6 Photosynthesis & Cellular Respiration

What is ATP?

Adenosine Triphosphate; cellular energy currency (cell batteries), contains three phosphate groups

What is ADP?

Adenosine Diphosphate; a product of ATP that contains two phosphate groups, used in energy transfer

What is the composition of ATP

Three phosphates connected to a 5 carbon ring with a nitrogen base hanging off it

What are some cellular processes that requires the cell to use energy?

Active transport, Growth, Reproduction, Nerve Signals, Muscle Contractionsf

What enzyme forms ATP?

ATP Synthase enzyme

What enzyme breaks down ATP into ADP?

ATPase enzyme

What is Phosphorylation?

The transfer of a phosphate group to a molecule

Describe the ATP cycle

ATPase Enzyme breaks the bond of one phosphate from ATP which releases some energy to be used for cellular work, the ATP turns into ADP which gains a phosphate through Phosphorylation, ATP Synthase enzyme forms ATP and energy is stored in ATP via cellular respiration

What is photosynthesis?

sunlight converted into P.C.B.E within glucose, occurs within the chloroplasts of producers/autotrophs

What are chloroplasts?

Membrane-bound organelles in autotrophs where photosynthesis occurs

What is Chlorophyll?

green pigment; absorbs red/blue wavelengths of light

What is the difference between Chlorophyll A and Chlorophyll B?

Chlorophyll A is a deep green pigment while Chlorophyll B is a yellow-green pigment

What are Accessory (Antennae) Pigments?

Help chlorophyll collect a greater amount of sunlight; broadens the absorption spectrum (Ex. Carotene and Xanthophyll)

What are Thylakoids?

membrane structures that contain photosystems; site of light dependent reactions

What are photosystems?

groups of enzymes that contain light absorbing pigments, located in between Thylakoids (Ex. chlorophyll)

What are Grana?

stacks of thylakoids; maximize membrane area for light absorption and photosystems; more membrane surface area = greater light absorption

What is Stroma?

cytosol like liquid of the chloroplast; site of light independent reactions

What is the Absorption Spectra?

Absorption by all pigments includes all wavelengths except green; reflected green light leads to green plant color

What is Transpiration?

water evaporating from the stomata

What are the two steps of photosynthesis?

occurs in two steps: Light Dependent / Light Independent reactions

What are Light dependent reactions?

require H2O and sunlight; water split, energy saved; Produce O2 as a waste product; Occurs in the thylakoid membrane / photosystems

What are Light independent reactions?

“Calvin Cycle“, require CO2, Produces glucose

What is the function of RuBisCO enzyme?

RuBisCO turns carbon dioxide into a usable / organic form

What is carbon fixation?

turning atmospheric carbon (in carbon dioxide) into a usable / organic form

What is the general Photosynthetic reaction?

H20 + CO2 —Light—> O2 + Glucose

What are Stomata?

Openings in plants that release O2 and absorb CO2, open or close depending on the amount of H2O and CO2 in the guard cells; lots of water in guard cells causing swelling / turgor pressure resulting in stomata opening

How do CAM plants photosynthesize?

Open stomata at night and close them during the day, water conserved; At night, they fix CO2 into a variety of organic compounds that can be released later during the daytime; Allows water conservation; slow growth but possible in deserts (Ex: Cacti, Jade)

How do C4 plants photosynthesize?

Contain special leaf cells that perform rapid uptake of CO2; allows for efficient photosynthesis during morning and evening; stomata close during the hottest part of day (Ex: Corn, crabgrass)

What is the role of NADP in photosynthesis?

acts as a crucial electron carrier in photosynthesis, transferring energy from the light-dependent reactions to the Calvin cycle, where sugars are made. During light reactions, it accepts high-energy electrons and a proton (H⁺) to become NADPH

What is Cellular Respiration?

the process by which cells break down organic compounds (i.e. glucose) to form ATP; ATP provides immediate energy for metabolic function

What is Anaerobic Cellular Respiration (Fermentation)?

Production of ATP without the presence of O2 or use of mitochondria; two forms of Anaerobic Cellular Respiration: Lactic Acid Fermentation and Ethyl Alcohol Fermentation

What is Lactic Acid Fermentation?

used by most bacteria and some animal muscle cells: Glucose —> 2 PGAL —> 2 Pyruvic Acid —> 2 Lactic acid + 2 ATP

What is Ethyl Alcohol Fermentation?

used by most yeast and some bacteria: Glucose —> 2 PGAL —> 2 Pyruvic Acid —> 2 Ethyl Alcohol + 2CO2 + 2ATP

What is Glycolysis?

the first stage in all forms of respiration; one glucose molecule is broken down into 2 pyruvic acid molecules; energy is released to phosphorylate 2 ATP molecules; occurs outside the mitochondria in the cytoplasm; no mitochondria / O2 required

What is Aerobic Cellular Respiration?

Requires the presence of O2 and mitochondria; produces much more ATP from 1 glucose molecule than anaerobic respiration (38 ATP); 19X more efficient

What are the four stages of Aerobic Cellular Respiration?

Glycolysis, Formation of Acetyl CoA, Krebs Cycle, and Electron Transport Chain