Download Plant Processes

Plant Processes
Section 1.2 p. 102-107
Learning Outcome
• Describe the process of diffusion, osmosis, conduction
of fluids, transpiration, photosynthesis and gas
exchange in plants
Question?
• If trees lack a heart to pump fluid around to its different components.
How does it move the necessary substances around?
Main Types of Plant Process’s
• There are different process’s that a plant must perform in order to
accomplish functions needed to sustain life
•
•
•
•
•
Process’s for moving water up from the roots
Process’s for making food
Process’s for using food
Process’s for moving substances in and out of plant Cells
Gas Exchange
Process for Moving Water up from the roots
• Water moves up from the roots to the leaves by a
combination of processes
• Water Has two main types of tissues for
moving nutrients
• Phloem: Moves Food
• Xylem: Moves Water
• Transpiration: H2O evaporates from the leaves and more
particles move up to fill their places; this moving up of
water molecules continues until it hits the roots
• Capillary Action: H2O travels from roots to leaves in tiny
tubes in the roots and stem. Water is a polar (positive and
negative ends) molecule and therefore creates an
attractive force with the sides of the capillaries allowing it
to overcome the gravitational forces
• Osmosis: Water from the soil enters the roots. If the
concentration of water is greater in the soil it will transfer
to the roots
Transpiration
• Transpiration: H2O evaporates from the leaves and more particles
move up to fill their places; this moving up of water molecules
continues until it hits the roots
• Think of it like a line up at a cashier in a store. As one person finishes paying
and leaving the rest of the line moves up
Capillary Action
• Capillary Action: H2O travels from roots to leaves in tiny tubes in
the roots and stem. Water is a polar (positive and negative ends)
molecule and therefore creates an attractive force with the sides of
the capillaries allowing it to overcome the gravitational forces
Osmosis
• Osmosis: Water from the soil enters the roots. If the concentration of water is
greater in the soil it will transfer to the roots
• Osmosis is exactly the same as diffusion, but refers to the movement of water molecules
only
• The water molecules will move from an area of high concentration to low concentration until equilibrium
is reached
The Plant Process’s for Making Food
• Just like plants do not have a heart to pump water and
nutrients from place to place they differ in the way they obtain
their nutrients.
• Plants are special when compared to humans
• They have two ways to obtain energy when needed
• Photosynthesis
• Photo meaning light,
• Synthesis meaning to create (a larger compound from simpler
compounds)
• Cellular Respiration
• This is the same process animals use to use Glucose (sugar) to
create ATP (Energy)
• What allows Plants to perform both processes, but not
Animals??
Difference is in their Cells
• All living things are made up of the basic
unit of life known as a Cell
• In these cells are what we call organelles
(structures) that allow certain functions
necessary to the cells survival to be
performed
• Plant and Animal Cells are very similar, but
contain a few key differences
• Animal Cells have an organelle known as the
mitochondria which acts as the power plant producing
energy needed by the cell to live
• Plant Cells have a different organelle that acts as its
primary power plant known as the Chloroplast
• But they also contain a smaller number of Mitochondria
Chloroplast’s
• Is an organelle (structure) found only in plants
• It contains a chemical inside known as Chlorophyll that reacts with the sunlight,
using it’s energy to produce food for the plant
• Chlorophyll in most cases absorbs all the wavelengths of light except green, which is then
reflected. Causing Leaves to appear green
Process of Photosynthesis
• The process of Photosynthesis uses the following reaction
Cellular Respiration (Using Food to Create Energy)
• Photosynthesis is only practical when light is readily available
• Sometimes plants go through periods when sunlight is limited
• When sunlight is unavailable the plant will use the stored sugars
(glucose/starch), and perform the process of Cellular Respiration
• The Equation for Cellular Respiration looks like this (does this look familiar??)
Processes of moving Substances in and Out of Plants
• Moving Water, Nutrients, and Gases in a plant are crucial for a plants
survival
• 3 Main Ways
• Diffusion (food, nutrients)
• Osmosis (Water)
• Active Transport (for substances found in the soil in short supply)
Uptake of Substances
Plants
• Diffusion
• Osmosis
• Active Transport
Animals
• Ingestion
• Absorption
Cell Membrane and Diffusion
• The Cell Membrane (gateway) acts like a filter that has small openings
allowing some particles to pass through
• Because it does not allow all particles to pass we refer to it as
selectively permeable
• Movement across the cell membrane occurs due to diffusion
• Concentration of O2 will be higher on the outside of the cell, so O2 molecules
diffuse across the membrane into the cell
Plants- Diffusion
• Diffusion: is the movement of
molecules from an area of
higher concentration to one of
lower concentration
• Think of it like an evening out or
balancing of the concentration
• No energy is required
• Nutrients move into the roots
of plants by diffusion
• High concentration in the soil
• Low concentration in the ground
Plants- Osmosis
• Osmosis: Water move across a membrane from an area of
high concentration to low concentration
• This occurs in plants in the roots
• Water rich soil, water poor roots will receive water molecules until
equilibrium is reached
Plants- Active Transport
• Active Transport: is a process in which plant cells use energy
to move nutrient molecules from areas of lower
concentration to areas of higher concentration
• This will force the movement of nutrients in the opposite direction
of diffusion
• Substances such as
• Nitrogen, phosphorus, sulfur, potassium may be needed by the roots of the
plants in greater quantities than what is available in the soil. Therefore
relying on diffusion would be insufficient
• Often occurs due to gated channels
Exchange of Gases
• Occurs in the Leaves
• Due to the process of Photosynthesis there is a constant exchange of Carbon
Dioxide entering the leaves, and Oxygen leaving into the atmosphere
• No different then us with our lungs and respiratory system
• Occurs through little openings (pores) in the Leaves known as Stomata’s