Unit 6 - Plant nutrition Flashcards
Photosynthesis word equation
Carbon dioxide + Water –> Glucose + Oxygen
Chlorophyll
- Green pigment present in the chloroplasts of plant cells
- Absorbs light energy
Uses of carbohydrates in plants
- Energy source - some glucose produced by photosynthesis is broken down in respiration for energy
- Storage - converted to sucrose for root growth and transported in phloem to the plant or converted to starch for storage
- Structural support - glucose converted into cellulose
- Assist pollination - glucose used to make nectar which attracts animals
Use of magnesium ions in plants
- At the centre of each chlorophyll molecule - needed for correct function
Use of nitrate ions in plants
- Making amino acids - make proteins
Limiting factor
A factor that prevents a rate from increasing
Factors that affect photosynthesis
- Light intensity
- Carbon dioxide concentration
- Temperature
Leaf adaptations
- Large surface area - exposes larger area to sunlight and air which helps ease absorption of materials
- Thin - ensures carbon dioxide can diffuse quickly and helps light penetrate easily
Structures of a leaf cell
- Cuticle
- Chloroplasts
- Upper epidermis
- Palisade mesophyll layer
- Xylem
- Phloem
- Vascular bundle
- Lower epidermis
- Guard cell
- Stomata
- Air spaces
- Spongy mesophyll
Cuticle function & adaptation
- Stops water from evaporating from the leaf
- Waxy layer
Chloroplast function & adaptation
- Site of photosynthesis
- Contains chlorophyll to absorb light and enzymes and structures needed for photosynthesis
Upper epidermis function & adaptation
- Protects the inner cells
- Thin layer without chloroplasts to let light pass through for photosynthesis
Palisade mesophyll layer function & adaptation
- Tissue in which photosynthesis happens
- Box-shaped cells that pack closely - lots of chloroplasts pushed to edges of cell by large vacuole to absorb more light
Xylem function & adaptation
- Carries water and mineral ions from the roots to the leaves
- Made from dead cells to form a hollow waterproof tube for water
Phloem function & adaptation
- Carries sucrose away from the leaf
- Consists of sieve tubes and companion cells to provide energy for transport
Vascular bundle function
- Contain the xylem and phloem tissues
Lower epidermis function & adaptation
- Protects the inner cells
- Thin layer that has no chloroplasts (except guard cells) to let light pass through for photosynthesis
Guard cell function & adaptation
- Work in pairs to control the size of stomata opening
- Entry and loss of water from guard cells results in change of shape - leads to opening and closing of stomata
Stomata function & adaptation
- Controls the diffusion of water vapor and gases in and out of the leaf
- The size of the opening changes in response to the internal and external environments of the plant
Air spaces function
- Allow diffusion of gases throughout the leaf
Spongy mesophyll function & adaptation
- Site of gas exchange
- Cells are loosely spaced, creating air spaces to allow diffusion of gases throughout the leaf
Hydrogencarbonate indicator colors
- Low levels of CO2 - red–> purple
- High levels of CO2 - red –> yellow
Use of lipids in plants
- Energy source in seeds
- Synthesis of new cellular material - membranes
Use of amino acids in plants
Make proteins to facilitate growth
Elements in amino acids
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
Plants with nitrate deficiency
- Stunted growth
- Yellowing of leaves
Starch test procedures
- Boiling leaf at start - kill cells and break down cell membranes
- Heating ethanol in a water bath - to avoid ethanol catching on fire since it is flammable
Plants with magnesium deficiency
- Yellowing of leaves
