Introduction to Plant Biology
First off: What is a plant?

Domain?

Kingdom?

Categories?
What does a plant need?
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Water

Sunlight
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Nutrients
How do they get them?
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Plant cells are specially designed to help the
whole plant get everything it needs
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These cells make up the plant structure,
which is designed to optimize
photosynthesis, hydration, and nutrition
Recall: Eukaryotic Cells

What are some things that all eukaryotic cells
have? What do these things do?  2 mins
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Eukaryotic cells have: A Nucleus, DNA in
Chromosomes, Mitochondria, Golgi Bodies,
Cell Membranes, Endoplasmic Reticulum,
Ribosomes, Vesicles, and proteins of all
kinds doing all sorts of different things
What a plant cell different?

A large, central vacuole
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A cell wall composed of cellulose
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Chloroplasts, which allow the plant to convert solar
energy into sugars

Plasmodesmata, which allow plant cells to
communicate
Large Central Vacuole

Filled mostly with water

In standing plants, gives the plant internal
support to allow rigidity (called turgor) Demo

Also used as a massive storage space, for
wastes, cellular materials, and water
Cell Wall Composed of Cellulose

Cell wall has a similar function in plants to
that in bacteria:
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Protects the plant cell against physical
damage, and gives it external structural
support to form its shape

However, made of different material...
Cellulose!
Structure of Cellulose
In contrast... Bacterial Cell Wall
Chloroplasts

Chloroplasts use the following formula to
convert sunlight into sugars:
Sunlight + CO2 + H2O  C6H12O6 + O2

Sugars then link up to form starch, which is
how they are stored until they are needed
Aside: Endosymbionts

Endo = Inside/Within, Sym = Together, Biosis = Living

Chloroplasts (and mitochondria) are thought to have
evolved as their own little microscopic organisms, with
their own genome and their own structure

At some point in cellular history, they were absorbed
by a distant eukaryotic ancestor, and now are used to
perform metabolic tasks inside our cells
Plasmodesmata

Occur only in plants living as multicellular
organisms

They are pores between plant cells, which
allow the transport of nutrients, wastes,
proteins and RNA

Can also allow viral particles to get through...
Recall: TMV

Can transport itself between targets using
the plasmodesmata as a way through
In Summary:

Plants are not bacteria  Nucleus,
Membrane-Bound Organelles, Cellulose

Plants are not protists  Complex,
Multicellular, Plasmodesmata, Differentiated

Plants are not animals  Cell Wall,
Chloroplasts, Photosynthesis, Vacuole
Plants are Plants!