Ecology

Question 1

What is the process of cellular respiration? (mitochondria parts)

Answer 1

Controlled release of energy from glucose to form ATP (adenosine triphosphate)
ATP → ADP (adenosine diphosphate) + P (recycled by adding inorganic P with glucose energy)
C6 H12 O6 + 6O2 → 6CO2 + 6H2O + energy

Mitochondria has outer membrane, wavy inner membrane, inner matrix

Glycolysis: cytosol of cell (1st step, few min)
Glucose → 2 pyrovate → yield 2 ATPs
Does not require oxygen

Oxygen present (aerobic, long time)
Krebs cycle: matrix of mitochondria; pyruvate → CO2 and 2 ATPs
Energy leftover (NAD+)
Electron transport chain: inner membrane of mitochondria; NAD+ electrons passed along, releasing energy, to water → 34 ATPs per glucose
Total: 38 ATP/glucose

No oxygen present (anaerobic, 2 min)
Lactic acid fermentation: cytosol of cell; pyruvate → lactate to blood, liver → oxygen debt
In liver: lactate → pyruvate (need oxygen); use in krebs and ETC or store as glucose in glycogen
Total: 2 ATP/glucose

Question 2

Describe energy and biomass pyramids

*units

Answer 2

Energy pyramid: flow of energy from one tropic level to the next in a community
kJ/m2/yr; 1% of sunlight to 1°p, 10% in following levels
Heat loss, unconsumed parts, unused parts (fiber) make up 90% of energy

Biomass pyramid: total dry mass of all organisms (g/m2); more dramatic than energy pyramid

Question 3

What are the parts (chloroplasts, cells, pigments) and processes of photosynthesis?

Answer 3

Chloroplast organelle: cytoplasm is stroma, thylakoid rings are connected and have membrane

Gas exchange and evapotranspiration via stomata:
Epidermal (outer) cell, stomatal pore between 2 guard cells
Pore opens / closes for in CO2, out O2

6H2O + 6CO2 + light energy → C6 H12 O6 + 6O2
Light reactions: split H2O into oxygen (byproduct) and hydrogen; form ATP from ADP+P and NADPH from NADP+ to go to Calvin cycle
Calvin cycle fixes (inorganic → organic) CO2 to make sugar; requires hydrogen and energy

Chlorophyll A and B are the main photosynthetic pigments of plant, cause color change when die in fall
Carotenoids are accessory pigments

Question 4

How do greenhouse gases work?

Answer 4

25% - 30% of short wave solar radiation absorbed by atmosphere; most of rest converts to heat
Earth surface re-emits long wave radiation, 70% - 85% captured by greenhouse gases
Greenhouse gases warm earth (without it would be cold)
Different gases insulate and last differently