Respiration and Water (Lecture 15) Flashcards
Fate of glucose in plants
- respiration (energy production ATP) PRIORITY 1
- growth (cellulose, lignin, DNA, amino acids, etc)
- Storage (conversion to sucrose and storage as starch)
Respiration and photosynthesis are _______ reactions
INVERSE
Respiration
process in which living things convert oxygen and glucose to carbon and water. does not need sunlight
2 major steps of respiration
glycolysis (cytoplasm) and Krebs cycle (mitochondria)
Glycolysis
6 carbon glucose is split into two 3-carbon pyruvate molecules, and some ATP and NADH are produced
Consumes 2 ATP, produces 4 (net gain is 2)
Krebs cycle
from glycolysis, these smaller carbon units enter the Krebs cycle where they are broken down into CO2 and NADH and FADH2 are released
NADH and FADH2 enter an electron transport chain where ATP and water are generated
Maintenance respiration
associated with protein and membrane turnover and maintenance of ion concentrations and gradients
Growth respiration
associated with synthesis of new structures in growth, nutrient uptake, phloem loading
A plant needs ___________ carbon balance to grow
positive
Net photosynthesis
the light compensation point (LCP) is the light level where carbon input from photosynthesis offsets losses from respiration
Water
most important factor for growth and distribution
Turgor pressure
necessary for cell enlargement, growth, and even form maintenance in some plants. also regulates stomatal opening/closing
Wilted leaves have ___________
Zero turgor potential
Cohesion-tension theory
The gravitational potential/weight of water pulls it downward. adhesive forces create friction, so to pull water up, there has to be negative water potential
