Structure and Function of the Cell
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Transcript of 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 Bacterial Cells
Parasitic CellUlcer causing bacteria cells
Your body has over 200 different types of cells!
Cell Size
Most cells are microscopic
Cell size is limited by the surface area tovolume ratio
Cell Shape
Shape is determined by the function of the cell
Internal Organization
Prokaryotic Vs. Eukaryotic Cells
“Before Nucleus”
No Nucleus or Membrane organelles
Single cell organisms
“True Nucleus”
Yes Nucleus and Membrane organelles
Multicellular and singleCell organisms
Surface Area to Volume Ratio
Surface Area : L x W x # of sides
Volume: L x W x H
Ratio : 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. A nucleus
3. 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”
Location: highly active cells
Rough Endoplasmic Reticulum
Function: Makes proteins, glycoproteins, and membranes for export out of the cell
Covered in ribosomes Location: surrounds
nucleus in cells that produce many proteins
Smooth Endoplasmic Reticulum
Function: Makes lipids, metabolizes carbohydrates, and detoxification center for the cell
Location: abundant in liver, kidney, ovaries, and testes
Ribosomes
Function: Protein synthesis
Location: 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
Location: found in most cells
Lysosomes Function: Digests
(breaks down) macromolecules the are in the cell, such as proteins and carbs.
Also breaks down dead cells
Location: abundant in liver and white blood cells
Peroxisomes Function: Breaks
down fatty acids Detoxification
center in liver cells
Location: abundant in liver and kidney 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
Location: contains organelles in cell
Cilia and Flagella
Function: Locomotion and movement of materials around the cell
Location: outside of 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 Location: “green
parts” of plant In plant cells
Central Vacuole
Function: Stores materials especially water and waste products
In plant cells