Biology Unit 4

Xylem

Water conducting tissue, long cells

Phloem

Nutrient carrying tissue, long cells

Water transport includes

Water cohesion and Capillary action

Water Cohesion

Water molecules attracted to molecules, make hydrogen bonds

Capillary action

The thinner the tube, the higher the water rises

Guard cells

Surround and control the opening and closing of the stomata

Leaf cross section

Enables photosynthesis, gas exchange, and water transport

Mesophyll

performs photosynthesis + facilitates gas exchange

Regulates opening and closing of stomata in guard cells

water pressure and high transpiration

High transpiration

wilting and loss of water pressure

Roots

absorb water

Waxy cuticles

prevent water loss

Guard cells

prevent water loss when necessary

Membranes in root epidermis

transports nutrients from soil to plant

Sugars move from source to sink

ATP then osmosis and pressure transports sugars to places in need

Auxins

hormones that cause cell elongation and growth

Ethylene

hormone and gas that seals the cell off from the plant

Photoperiodism

short day plants flower in long darkness, long day plants flower in short darkness

Phototropism

grow towards light source

Gravitropism

plants respond to gravity

Thigmotropism

plants respond to touch

Plants grow in low nitrogen soils

break apart insects for nitrogen

ATP

made up of adedine, ribose, and 3 phosphate groups, stores and releases energy

ADP

similar to ATP but has 2 phosphate groups

Photosynthesis

converts sunlight into chemical energy stored in bonds of carbohydrates (sugars and starches)

Balanced equation for photosynthesis

6CO2 + 6H2O =light= C6H2O6 + 6O2

Photosynthesis uses Pigments

to capture sunlight energy

Autotrophs use pigments

to absorb sunlight for energy products

Heterotrophs

don’t use pigments and and consume heterotrophs for energy

Light dependent reactions

require direct light and pigments

Hydrogen ions path

made in thylakoid & passes thru ATP synthase and phosphate group (binds ADP)

Electrons in light dependent reactions

low energy electrons in water molecules to high energy levels to NADP to NADPH

NADP

electron carrier

Products of light dependent reactions

provides energy in reactions in the 6 carbon dioxide molecules to a single 6 carbon sugar molecule

CO2 producing products in carbon cycle

for every 6 carbon dioxide molecules, 12 3 carbon compounds are produced, turning into higher energy forms

Translocation

doesn’t rely on hydrogen bonding