Chapter 2 – Cell structure & the cell cycle. Plant Cells.

Chapter 2 – Cell structure & the cell cycle

Plant Cells

What distinguishes plant cells?

Plastids (chloroplasts, etc.) Cell wall Large central vacuole Plant cell specific connections

Where are the chloroplasts?

Plastids– Chloroplasts– Leucoplasts

Amylopasts Elaioplasts (niyb)

Plastids - Chromoplasts

Chloroplasts, mitochondria and endosymbiosis

Chloroplast Genome

Circular DNA molecule Replicate independently Sequence characteristics

resembles that of bacteria

Paramecium with endosymbiont Chlorella

Plant cell walls Primary cell walls Secondary cell walls

-for structural support

Cell walls Pectins (proteins) and hemicelluloses

(carbohydrates) link cellulose molecules together

Cell Walls

Lignin strengthens & waterproofs secondary cell walls

Plant cell connections

Middle lamella (pectins) hold cells together

Bordered pits speed water and solute diffusion through cells with secondary cell walls

Bordered pits

Plant cell connections

Plasmodesmata provide cytoplasmic connections between cells

Plasmodesmata

Cytoskeleton

Microtubules Microfilaments Motor proteins

(walking molecules)

Movement in plant cells and the cytoskeleton

Plant cell research

Plasmodesmata