Download Intro to Cell Notes

“Life is Cellular”
Since the invention of the microscope
Scientists have been able to discover a world that could
have never been imagined
The Scientists involved in the
Cell Theory

In 1665 Robert Hooke
looked at a slice of cork
under a microscope


The tiny chambers reminded
him of the “cells” in a
monastery so he called them
cells
In 1674 Anton von
Leeuwenhoek made better
lenses for the microscope
and was able to see cells in
greater detail
The Scientists involved in the
Cell Theory

In 1838 and 1839 Matthias
Schleiden and Theodore
Schwann observed that all
living things are made up of
cells



Schleiden noted that all plants
are made up of cells
Schwann stated that all
animals are made up of cells
In 1855 Rudolf Virchow
states that all cells come
from pre-existing cells
The Cell Theory
 All
living things are composed of cells
 Cells
are the basic functional units of life
 New
cells are produced from existing cells
Prokaryotes vs. Eukaryotes
 Prokaryotes
 Eukaryotes
 smaller & simpler
 Have a nucleus
containing DNA
 Contain a cell
membrane &
 Most have specialized
cytoplasm
structures called
organelles
 No nucleus
 All plants, animals, and
 All bacteria are
fungi are eukaryotes
prokaryotes
 DNA is “free – floating”  Larger and more
complex
Prokaryote vs. Eukaryote
Cell membrane
Cytoplasm
Prokaryotic Cell
Prokaryotic Cell
Cell membrane
Cytoplasm
Nucleus
Eukaryotic Cell
Organelles
Eukaryote Cell Structures
 Cell


Wall
Found in many
organisms including
plants, algae, fungi,
and nearly all
prokaryotes
Not found in animal
cells
Cell Wall
The main function
of the cell wall is
to provide support
and protection for
the cell
Plant cell walls are
made of cellulose
The Nucleus
 The
nucleus is the “brains” of the cell
 The
nucleus controls most cell processes
and contains the hereditary information of
DNA
 Almost
all eukaryotic cells, including plant
and animal, contain a nucleus
The Nucleus
Nucleolus – small
dense region in
nucleus where
ribosomes are
produced
 Nuclear envelope –
double membrane
layer surrounding
the nucleus (aka.
Nuclear membrane)

The Cytoskeleton

A network of protein
filaments that help the
cell maintain it’s
shape
 It is also involved in
many forms of
Microtubule
movement
Microfilament
The Cytoskeleton
 Made



up of three types of structures:
Microtubules – hollow tubes of protein that help
maintain cell shape and serve as “tracks” for
organelles to travel on
Intermediate Filaments – smaller than
microtubules – gives a cell its strength
Microfilaments – long thin fibers that support cell
movement and support
Organelles in the Cytoplasm

Ribosomes



Site where proteins
are made
A ribosome is a protein
and an rRNA
(ribosomal RNA)
Ribosomes make
proteins from the
“coded” instructions of
the nucleus and the
DNA
Ribosomes
Endoplasmic Reticulum


An internal membrane
where parts of the cell
membrane are made and
some proteins are
modified
Rough
endoplasmic reticulum
The Rough
Endoplasmic Reticulum
is where protein synthesis
occurs
 Ribosomes are on it’s
surface making it
appear “rough”
Endoplasmic Reticulum
 The
Smooth
Endoplasmic
Reticulum does
not have any
ribosomes on it’s
surface

It contains
enzymes that
make lipids (fats)
Smooth endoplasmic
reticulum
Golgi Apparatus
Golgi apparatus

After proteins are assembled and produced by the
Rough ER they move to the Golgi Complex where :


Carbohydrates (sugars) and lipids (fats) are attached to the
protein
They are then sent to their final destination
Lysosomes
 Small
organelles that are
filled with digestive and
other enzymes



They break down lipids
(fats), carbohydrates
(sugars), and proteins from
food particles so it can be
used by the rest of the cell
Lysosomes also break
down “old” organelles that
have outlived their function
Basically, they “take out the
trash”
Vacuoles

Serve as a storage for
water, salts, proteins,
and “carbs” (plant and
animal cells)
 In Plants :

They usually have one
large vacuole filled
with water to support
structures like leaves
and flowers
Vacuole
Chloroplasts
 The


producer!
They use sunlight to
power a familiar
process called
Photosynthesis
The green pigment
(color) chlorophyll is
what gives leaves
their color and is
found inside
chloroplasts
Chloroplast
Mitochondria
 The
“powerhouse” of
the animal and plant
cell!



Mitochondria use energy
from food to make highenergy compounds
The cell uses these highenergy compounds for
growth, development, and
movement
In that way, the
mitochondria makes “fuel”
for the cell
Figure 7-5 Plant Cells
Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi
apparatus
Nucleus
Mitochondria
Rough endoplasmic reticulum
Plant Cell