Plant Biology- Lecture #1 and #2- plant cells, organelles, and cell walls

The four groups of embryophytes

non-vascular plants(mosses)

seedless vascular plants

seed plants with flowers(angiosperms)

seed plants with “hacked seeds” (gymnosperms)

The major components of a plant cell

• Cell wall

• plasma membrane

• protoplast (all except the wall)

• cytoplasm (Liquid in the cell)

• nucleus

• organelles

• vacuole

what are Plastids?

Organelles found only in plants and some algae

• they have a double membrane (outer and inner bilayers)

  -contain DNA and ribosomes

  -grow and divide similar to bacteria

  -There are 6 types of plastids

Proplastids

• Small, undifferentiated plastids

• found in young cells

  -In light hey can turn into chloroplast

• in dark, can develop to other plastids

Chloroplasts

• Contain green pigment called chlorophyll

• site photosynthesis

  -complex internal structure

chromoplasts

yellow, orange, red pigments (eg. Carotenes, xanthophylls)

-lipids- soluble

often present in flowers, fruits and leaves

Leucoplasts

colorless

synthesize oils, proteins, other materials

Amyloplast

stores starch

involved in gravity response

Elaioplasts

Store oils

-another type leucoplast

vacuole

• Large membrane-bound organelle

• surrounded by a single membrane

-Functions in storage for

• Water

• salts

• minerals

• metabolites

Plant metabolites- Primary metabolites

found in all plant cells

-necessary for life

• lipids, amino acids carbohydrates

Plant metabolites- secondary metabolites

found only in some cells

function in defense, signaling

-alkaloids, terpenoids, cardiac glycosides