Essential Questions
Describe the different
scientist and their
contributions to
science, dealing with
cells?
Who made the first
microscope?
What did Robert
Hooke discover in
1665?
What two discoveries
were made in the
1830s?
Who wrote the Cell
Theory?
What is the cell
theory?
What are the two cell
groups?
What are the outside
structures and what
are their functions?
Describe the different
organelles and there
functions.
How are plants and
animals cells alike and
different?
What are the levels of
organization of an
organism?
Cell Structure, page 221: section 3
Antonie van Leeuwenhoek made the first simple microscope.
Cell Theory
1665, Robert Hooke cut a thin slice cork and studied it under a
microscope. He discovered small boxes that looked like cells at a Jail. So
he named them cells.
1830s Matthias Schleiden studied plants and discovered plants were
made of cells. Theodor Schwann observed that animals were also made of
cells, during this time.
Mid 1800s Rudolf Virchow hypothesized that cells divide to form new
cells. He used his own studies and the observations of other scientist to
write the Cell Theory.
Cell Theory
1. All organisms are made up of one or more cells
2. The cell is the basic unit of organization in organisms
3. All cells come from preexisting cells
Cellular Organization
2 groups:
1. Eukaryotes: cells with membrane-bound organelles inside the cell.
2. Prokaryotes: cells without membrane-bound organelles.
Cell Wall: plants, algae, fungi, and bacteria have cell walls. They are tough,
rigid covers that protect cells and give them shape.
Cell Membrane: all cells have a cell membrane. It covers the cell and
regulates what enters and leaves the cell.
Cytoplasm: Cells are filled with a jellylike liquid. Contains cytoskeleton to
help maintain or change its shape.
Ribosomes: Every cell needs protein in order to carry out life processes.
This means every cell needs Ribosomes. Ribosomes float in the cytoplasm
or attach to endoplasmic reticulum. Are not surrounded by a membrane.
Membrane-bound organelles (only Eukaryotes)
Nucleus: Directs all cellular activities. Contains DNA.
Chloroplast: only in plants. Responsible for photosynthesis, contain green
chemical called chlorophyll. Captures light from the sun to make glucose
(food).
Mitochondria: Responsible for cellular respiration. Breaks down glucose
(food) in order to make energy (ATP).
Endoplasmic Reticulum (ER): Cell highway, folded transport membranes
that extend from nucleus. Two types Smooth and Rough. Rough ER has
ribosomes attached to it.
Golgi Bodies: are stacks of flattened membranes that transport proteins
in and out of the cell.
Vacuole: stores water, waste, food, and other cellular materials. Animal
cells have small sacks, while Plant cells have large central vacuoles.
Lysosomes: Contain digestive chemicals to break down food, waste,
worn-out cell parts, viruses, and bacteria.
Levels of Organization
Cells make Tissues, Tissues make Organs, Organs make Organ Systems,
Organ Systems make Organism