Biology of Plants

1
Chapter 3
Introduction to the Plant Cell
2
Outline

• Intro
• Comparsion of prokaryotes and eukaryotes
• Overview of plant cell
• Cell parts
• nucleus
• chloroplasts and plastids
• mitochondria
• peroxisomes
• vacuoles
• ER
• golgi apparatus
• cytoskeleton and flagella/cilia
• cell wall and plasmodesmata
• cell cycle (interphase/mitosis/cytokinesis)

3
Intro

• 1660s Hooke - 1st to describe cells
• 1838 Scheiden - all plant tissues consist of
  cells
• Schwann - all animal tissues consist of cells
• 1858 Virchow - all cells arise from preexisting
  cells
• 1859 Darwin On the Origin of Species
• Cell Theory
• all life composed of 1 cells
• chemical rxns of living organisms take place in
  cells
• cells arise from other cells
• cells contain hereditary information that is
  passed on

4
Prokaryotic and Eukaryotic Cells

• All cells have plasma membrane (PM) (a.k.a.
  plasmalemma/cell membrane) and genetic material
• Prokaryotes
• 1st life was prokaryotic
• single, circular chromosome
• no membrane bound nucleus but nucleoid region
• Eukaryotes
• linear chromosomes bound to histones
• distinct nucleus surrounded by double-membraned
  nuclear envelope

5
Prokaryotic and Eukaryotic Cells

• Rest of cell other than nucleus/nucleoid
  cytoplasm
• Cytoplasmic contents
• both prokaryotes and eukaryotes
• ribosomes (protein syn.)
• CWs (diff. structure and func. in prokaryotes and
  eukaryotes)
• eukaryotes
• membrane-bound organelles
• presence of cytoskeleton
• larger
• prokaryotes
• lack membrane-bound
  organelles
• lack of cytoskeleton
• smaller

6
(No Transcript)
7
Plant Cell Overview

• Plant cell consists of CW and protoplast
• protoplast cytoplasm and nucleus
• cytoplasm bound by PM, includes organelles,
  nonmembranous structures, and cytosol (cellular
  soup)
• Plants have vacuoles (fluid-filled cavity) bound
  by membrane called tonoplast
• Cytoplasmic streaming (cyclosis) mvmt of
  cytoplasm

8
(No Transcript)
9
(No Transcript)
10
Plasma Membrane

• 3-layered appearance
• Func.
• mediate transport into/out of cell
• coordinates syn. and assembly of cellulose of CW
• transmits hormonal/environmental signals which
  control growth/differentiation
• Composed of lipid bilayer w/ proteins

11
Nucleus

• Func.
• controls cellular activities (protein syn.)
• stores genetic info.
• Bound by double membrane bound nuclear envelope
• nuclear pores exchange materials btwn
  nucleus/cytoplasm
• outer membrane continuous w/ ER
• Contains chromatin (DNA histone proteins that
  form chromosomes)
• chromosomes visible during mitosis
• haploid v. diploid, gametes v. somatic cells
• Nucleolus w/i nucleus
• site of ribosome syn.

12
Chloroplasts and Other Plastids

• Ashleys presentation