Download Structure and Function of the Cell

Structure and Function
of the Cell
Chapter 4
4.1 Discovering the cell…
 1665
– Hooke looked at plants under
the microscope and saw little boxes
– He named them “cells”
 1673
– Van Leeuwenhoek was the
first to see living cells
Fast Forward…150 years!




Schleiden – all plants are composed of
cells
Schwann – all animals are composed of
cells
Virchow – cells come only from other cells
These three scientists’ work lead to the
modern CELL THEORY
The Cell Theory
1. All living things
are composed of
cells
 2. Cells are the
basic unit of an
organism
 3. Cells only come
from the
reproduction of
preexisting cells.

Cell Diversity
Red Blood Cells
Ulcer causing bacteria cells
Bacterial Cells
Parasitic Cell
Your body has over 200 different
types of cells!
Cell Size
Most cells are microscopic
Cell size is limited by the surface area to
volume ratio
Cell Shape
 Shape
is determined by the function
of the cell
Internal Organization
 Prokaryotic
Vs. Eukaryotic Cells
“Before Nucleus”
“True Nucleus”
No Nucleus or
Membrane organelles
Yes Nucleus and
Membrane organelles
Single cell organisms
Multicellular and single
Cell organisms
Surface Area to Volume Ratio
 Surface
Area : L x W x # of sides
 Volume:
 Ratio
LxWxH
: surface area/volume
Now you try….
1.
Obtain a copy of the lab: Modeling
Cells: Surface Area to Volume AND
box paper
2.
Cut out boxes and tape them
together (3 boxes total)
3.
Complete lab worksheet about
surface area to volume ratio
All Eukaryotic Cells Have…
1.
A cell membrane
2.
3.
A nucleus
Other organelles
Parts of the Eukaryotic Cell
The structures are determined by the functions of each part
1. Cell Membrane
 Function:
outer layer of a cell that
allow substances into and out of the
cell
 Selectively
permeable – allows only
certain things to cross the membrane
Parts of the Membrane

Membrane Lipids
– Phospholipids
arranged due to
their hydrophobic
and hydrophilic
ends
– Lipid bilayer
– Steroid
(cholesterol)
embedded within
Parts of the Membrane (cont)

Membrane Proteins
– Peripheral proteins
– attached to either
side of the cell
membrane
– Integral proteins –
embedded within
the cell membrane
and extends out on
both sides
Fluid Mosaic Model
 Membrane
behaves like a liquid
– Lateral movement of lipids and proteins
 Mosaic
– changing pattern of
proteins and lipids in the membrane
Organelles
 “Mini
organs” of the cell
 Each
organelle has its own structure
and function
 All
cells have different types and
numbers of organelles
Nucleus


Function: to store the hereditary
information of the cell (DNA) and to
control the cell
Contains: nuclear envelope, nuclear
pores, nucleolus, and chromatin
(chromosomes)
Mitochondria


Function: makes
ATP
“Powerhouse of the
Cell”
Rough Endoplasmic Reticulum
Function: Makes
proteins,
glycoproteins, and
membranes for
export out of the
cell
 Covered in
ribosomes

Smooth Endoplasmic Reticulum

Function: Makes
lipids, metabolizes
carbohydrates, and
detoxification
center for the cell
Ribosomes
Function: Protein
synthesis
 Attached to E.R.
or free in
cytoplasm
 Made in nucleus
and completed in
cytoplasm

Golgi Apparatus
 Function:
Manufacturing,
warehousing, sorting,
and shipping materials
out of the cell
Lysosomes
Function: Digests
(breaks down)
macromolecules
the are in the cell,
such as proteins
and carbs.
 Also breaks down
dead cells

Peroxisomes


Function: Breaks
down fatty acids
Detoxification
center in liver cells
Cytoskeleton


Function: Support
system of the cell,
aid in movement
within the cell
3 Structural Types:
microtubules
microfilaments
intermediate filaments
Cytoplasm


Function: Holds
organelles in the
cell
Site of all chemical
reactions in cell
Cilia and Flagella


Function:
Locomotion and
movement of
materials around
the cell
Animal cells only
Cell Wall


Function: Protects
the cell, gives the
cell shape and
structural support
Plant cells
Chloroplasts
Function:
Photosynthesis
 Makes energy from
the sun
 In plant cells

Central Vacuole
Function: Stores
materials
especially water
and waste products
 In plant cells
