Exam 2 Flashcards
What do plants use water for?
Photosynthesis, temperature regulation, and stability.
Brownian motion
Ions and molecules are in constant random motion
Diffusion
Influenced by pressure, temperature, and density of the medium.
Osmosis
Diffusion through a semipermeable membrane where the concentrations equilibrate. The area of the higher concentration goes to the area of the lower concentration.
Cell water potential
Water enter cells through osmosis
Osmotic potential
The potential of water molecules to move from a hypotonic solution (more water, less solutes) to a hypertonic solution (less water, more solutes) across a semi-permeable membrane.
Pressure potential
Water moves from cells with higher wetness to cells that are dry.
Transpiration
The loss of water vapor from the leaves to the atmosphere. Occurs from root to leaf, water vapor exits stomata during photosynthesis
Guard cells
Epidermal cells, two of which create a stoma (singular stomata). They regulate gas exchange between the leaf and the atmosphere.
How guard cells open and close
By changing the turgor pressure. The more inflated the stomata is (more water and solutes in it) the more open they are.
Environment influence on transpiration rates
Transpiration increases with temperature, sunlight, high soil moisture, and wind velocity. Too high of a temperature causes a decrease in transpiration (due to the stomata closing), and high CO2 rates decrease transpiration.
Translocation
Movement of food substance throughout a plant via water.
Pressure-flow-hypothesis
Food is actively loaded into phloem from source. Water enters xylem and phloem via osmosis. Pressure gradient drives food down the phloem. Food is then actively removed from the sink.
CAM plants
Opens stomata at night versus the day. This type of plant collects CO2 at night to use the next day when the plant performs photosynthesis with its stomata closed. (EX: Cacti and orchids)
What do plants get from soils?
Nutrients, water, and stability
Why are desert soils infertile?
There is no rain to weather down the soil, which means there are no nutrients in the soil. Without nutrients or water in the soil, plants have nothing to grow from.
Sandy soils
Large pore size, obtain oxygen, and water, has good root growth, and is easy to work with. Water and nutrients drain out quickly.
Clay soils
Water drains slowly through this soil type, nutrients hold on better, but it has small pores and low oxygen levels, and it is harder to work with.
Loams
(Sand, silt, and clay combined) Best for agriculture due to different-sized pores, more space for growth, sand has a high pore size, clay holds moisture, clay and silt hold nutrients, and silt is “workable”.
Organic matter
Compounds that have a carbon base. Usually, C, H, O, and N. Produced by the decomposition of plants and animals.
Living and non-living things found in soil
Nutrients, water, microorganisms (bacteria and fungi), seeds, worms, organic matter, rocks, silt, sand, clay, roots, plant parts, and vertebrates (moles, prairie dogs, groundhogs, etc.).
Topsoil
Newly decomposed living organism, lots of organic material
B-horizon
Broken down materials and inorganic material
Parent material
Weather igneous and sedimentary rocks
Bedrock
The bottom layer of the soil
Soil water content
Soil structure, density of vegetation,location of ground water table
Wilting point
Point at which water is no longer available to plants, dependent on soil texture
Field capacity
Point at which soil can hold NO MORE water
Best pH in soil for plants
7
Metabolism
Any biochemical processes inside a living organism. Examples include photosynthesis, respiration, digestion, growth, movement in a living organism, and translocation.
Enzymes
Proteins that speed up and ultimately regulate metabolic processes
ATP
Adenosine triphosphate. Powers many chemical reactions, also known as “energy packets”. 3 phosphate groups, a lot of pent-up energy that is stored, and after splitting it creates ADP
The importance of photosynthesis
Without it the food chain would collapse, living organisms would slowly die, plants wouldn’t be able to convert CO2 into sugars, and the regulation of carbon on earth would end.
Major ingredients of photosynthesis
CO2, H2O, light, chlorophyll, enzymes, glucose, and oxygen + water.
Carbon Dioxide (CO2)
Diffuses into plant leaves through the stomatal opening and ultimately reaches the chloroplasts. It’s function is to provide C.
Water (H2O)
Solution for CO2 to dissolve and is the source of the electron involved.
Light
Provides energy for photosynthesis and absorbs in the red and blue portion of the spectrum
Chlorophyll
Molecules that absorb red and blue light. Not green
Enzymes
Catalyze the reactions, very temperature sensitive. (EX: Rubisco)
Glucose
Produced during respiration, lipid and starch formation and plant structure formation
Oxygen + Water
Byproducts of photosynthesis and may be recycled or emitted as gas through the leaves
Start products of light-dependent reactions
Light, H2O, NADP+, ADP, and P
End products of light-dependent reactions
ATP, NADPH, O2, and H+
Start products of light-independent reactions
CO2, RuBP, ATP, and NADPH
End products of light-independent reactions
ADP, NADP, 3C sugars, and RuBP
Oxidation
Removal of electron(s) from compound
Reduction
Addition of electrons
Light-dependent reaction steps
1) Photons of light are absorbed
2) Electrons get excited – Boosted to a higher energy level
3) Water is split
4) Electrons flow down the electron transport chain
5) ATP & NADH are produced (stored energy)
Light-independent reaction steps:
1) Take ATP and NADH from LDP
2) Convert CO2 into sugars
3) Restart the cycle
Calvin Cycle steps
It’s the process by which rubisco grabs CO2 out of the atmosphere and combine that with the 5C sugar to make glucose and make more 5C sugar (RuBP)
Rubisco
Oldest enzyme that hasn’t yet evolved, it grabs CO2 and starts the Calvin cycle
C3 photosynthesis
Most common form of photosynthesis
C4 photosynthesis
Separate carbon and sugar creation. Most grasses in the US and south US (hot & dry areas), involve a step with PEP
CAM benefits
Keeps stomata closed during the day which reduces water loss and uses PEPc instead of Rubisco which causes less photorespiration
Why do plants respire?
TO take glucose and create usable energy
Substrate for respiration
Glucose
Byproducts of respiration
Water, carbon, and energy
ADP
Adenosine diphosphate, 2 phosphate groups, result of ATP splitting, and can be recycled and used to make ATP
Start products of glycolysis
Glucose and ATP (2)
End products of glycolysis
Pyruvic acid and ATP (4)
Investment step of glycolysis
Use ATP to create 2 phosphorylated 3C sugars
Reward step in glycolysis
Use 2 phosphorylated 3C sugars to create ATP (4) and pyruvic acid
Electron transport system end product
ATP by taking reduced “energy packets” *NADH and FADH2) and converting to ADP and ATP
Anaerobic efficiency
6%
Anaerobic
Without oxygen
End product of anaerobic respiration
Ethyl alcohol
Energy
Primary product of respiration
Glycolysis function
Make some ATP and substrate for making [x] H
Citric acid cycle function
Make [x] H
Electron transport system function
Make ATP
Water use efficiency
Carbon gained per water lost
WUE formula
Photosynthesis divided by transpiration
How can WUE be improved?
The stomata must close
Carbon use efficiency
Carbon gained per carbon lost
CUE formula
Photosynthesis divided by respiration
Efficiency
The ratio of stuff produced to the stuff used
Net primary productivity
Photosynthesis - respiration
Photosynthesis
Using sun to create glucose
Respiration
Using glucose to create ATP
Plant A takes up 10 moL CO2 per 5 moL H2O lost, plant B takes up 5 moL CO2 per 1 moL h20 lost. Which one has a higher WUE, and which is the better competitor?
Plant B has a higher WUE (5/1=5), and Plant A is a better competitor (10/5=2)
CUE temperature
Photosynthesis and respiration have different short-term temperature sensitives; thus, CUE may change with temperature.
CUE acclimation
Given time, plants will acclimate to climate. Photosynthesis continues to increase, and CUE after acclimation is 2:1 (photosynthesis: respiration)
How do plants and animals facilitate plant nutrient uptake?
Plants and animals break down organic matter and release nutrients to soil and then to plants (by chewing things up and poop it out basically, plants provide most of the nutrients by recycling them into the soil)
How do plants regulate WUE?
WUE involves photosynthesis and transpiration the plant can use the stomata to up the WUE by closing the stomata or open them to do more photosynthesis
Why does increasing atmospheric CO2 positively influence WUE?
Higher CO2 in the atmosphere has a positive effect on photosynthesis, plants tend to close their stomata when CO2 goes up which would decrease transpiration which would also increase WUE
