lesson 5

Question 1

autotrophs

Answer 1

autotrophs: can build their own energy rich macromolecules
- photoautotrophs: plants use energy of light
- chemoautotrophs: (some bacteria) use energy of inorganic molecules (like ammonia or sulfur)

Question 2

heterotrophs

Answer 2

heterotrophs: animal, fungi, bacteria

Question 3

light reactions

Answer 3

light reactions

enters PS2 & funneled to reaction center (energizing electrons)

Question 4

photosynthesis starting materials
how is it absorbed?

Answer 4

CO2: stomata (holes)
H2O: roots
sunlight: pigments in leaves

Question 5

photosynthesis ending materials

Answer 5

glucose: stored as cellulose & starch
O2: released/waste product

Question 6

light energy

Answer 6

convert light energy into energy stored in chemical bonds

made of photons that travel in waves
short wavelengths(blue/purple): MORE energy
long wavelengths(red): LESS energy

the color of an object/ perceived color is determined by which wavelengths are REFLECTED off surface

Question 7

pigment proteins

Answer 7

each absorb diff wavelengths
chlorophyll a = primary pigment protein
accessory pigments: chloro b & b-carotene (absorb and transfer to chloro a)

Question 8

using graph to explain color of plants

Answer 8

green light is not absorbed, so it is reflecting
plants usually absorb blue light because it has most energy

Question 9

light reactions
location input output

Answer 9

thylakoid light
membrane H2O O2
NADP NADPH
ADP + Pi ATP

Question 10

calvin cycle

location input output

Answer 10

stroma CO2 glucose
NADPH NADP+
ATP ADP

Question 11

photosystems

Answer 11

group of photosynthetic pigments
- TRAP light energy
- found in thylakoid membranes
-each has a central reaction center
(chlorophyll a molecules & pair of special electrons)
^ (chlorophylls a special electrons convert light energy into chemical energy)
- collect light energy that is funneled toward reaction center, energizing chloro a special electrons -> ETC -> given to NAD+

Question 12

light reactions

Answer 12

light energy enters photo system 2 & is funneled to reaction center (reenergizing electrons)

electron carriers shuttle through ETC

electrons move through chain, this energy helps pump H+ into thylakoids lumen

at the end of etc, electrons -> photo system 1

electrons are energized again and are used to reduce NADP+ —> NADPH

ATP synthase uses energy of H+ moving back across thylakoid mem to generate ATP (through chemiosmosis)

Question 13

NADPH

Answer 13

energy storage molecule
electron carrier

Question 14

where each photo system gets its excited electrons

Answer 14

system 2: from water, generating oxygen
system 1: from system 2

Question 15

calvin cycle

Answer 15

goal: Carbon Fixation
- attaching carbon atoms to other molecules to generate organic macromolecules

• uses enzyme RUBISCO
• each time every step is completed, only 1 carbon is fixed
• must run 3 TIMES to generate 1 new molecule of G3P
• must run 6 TIME to generate one new molecule of glucose

Question 16

calvin cycle steps:

Answer 16

CO2 goes into cycle:
- attached to a 5-carbon compound (RuBP)
- eventually split into two G3P molecules- each w 3 C
- to build 1 glucose (6 carbons): cell needs to combine 2 G3P molecules