SBI4U – Grade 12 AP Biology – Metabolism Test

Thanks, Bairavi Sripalan!

Metabolism

Main Ideas Labs Plant Pigments & Photosynthesis & Cell Respiration

Energy flows into an ecosystem as sunlight and ultimately as heat, while the chemical elements essential to life are recycled.

http://kentsimmons.uwinnipeg.ca/cm1504/Image150.gif

Cellular Respiration

– About 40% of the energy in a glucose molecule is transferred to ATP during cellular respiration making about 36-38 ATP.

 

Glycolysis

– occurs in the cytoplasm

– During glycolysis each glucose molecule is broken down into 2 molecules of the compound pyruvate. In eukaryotic cells, pyruvate enters the mitochondrion

– From there it is oxidized to CO2. ATP is than generated.

– has 10 steps that are broken down into 2 main phases

 

http://www.accessexcellence.org/RC/VL/GG/ecb/ecb_images/13_03_glycolysis.jpg

1-3 energy is in the form of ATP. So ATP is hydrolyzed to ADP in two steps

7-10 glycolysis substrate level phosphorylations occur. The formation of ATP through the transfer of a phosphate group to ADP

Krebs cycle / Citric Cycle

– occurs in the matrix of the mitochondria

– active transport

– only occurs when oxygen is present, and processes lipids, proteins and carbohydrates

 

Oxidative Phosphorylation

– amounts for the most energy extracted from food

– has two stages

– Electron transport chain

– Pumps in the christae

– Moves the NADH and FADH2 => redox power

 

– Chemiosmosis

– H+ passes through ATP synthase

– ATP synthase makes ATP

 

Glucose è NADH è E.T.C. è Proton Motive Force è

Fermentation (Anerobic)

– Uses an electron transport with an e- acceptor other than O2

– Fermentation uses phosphorylation instead of electron transport chain to generalize ATP

 

Photosynthesis

– Process that converts solar energy into chemical energy

– Consists of the light reactions & calvin cycle

 

Mesophyll – are where chloroplasts are found, are located in the middle of the leaf and have about 30-40 chloroplasts

Thylakoids – contains the chlorophyll; connected sacs in the chloroplasts

Chloroplast è Granum (Grana) è Thylakoid è Chlorophyll *stroma is the matrix of the chloroplast

Light reactions

– Splits water molecules

– Releases O2

– Reduce NADP+ to NADPH

– Generate ATP from ADP by photophosphorylation

 

Calvin Cycle

– Forms sugar from CO2; ATP + NADPH

– Carbon fixation (incorporating CO2 into organic molecules)

 

Pigments

– pigments absorb visible lights

– different pigments absorb different wavelengths; wavelengths that are not absorbed are reflected or transmitted

 

Plants

– most plants are C3 plants

– photorespiration and O2 is used by rubisco

– C4 plants

– – to minimize the cost photorespiration into 4-carbon compounds

– CAM

– – opens their stoma at night and close during the day.