Cell structure Mrs. Dalia Kamal Eldien Practical NO 1

Cell structure

Mrs. Dalia Kamal EldienPractical NO 1

CELLS

Structure and Function

Cell = smallest unit of life

Two Major Cell Types

Cell Type Example

Prokaryotic Bacteria

Eukaryotic ProtistsFungiPlants

Animals

Prokaryotic Cell

Eukaryotic Cell (protist, animal)

Eukaryotic Cell (plant)

Differences Between Cell Types

Prokaryotic Cell Eukaryotic Cell

Single circular chromosome Multiple linear chromosomes

Chromosome found in a cytoplasmic region called the nucleoid.

Chromosomes found in a membrane-bound nucleus.

No internal membranesSome infolded plasma membrane

Extensive network of internal membranes

Common Components and Cellular Organization

• Plasma Membrane– boundary surrounding the cell

• Genetic material: DNA– located in a membrane-bound nucleus

for eukaryotic cells• Cytoplasm

– Semi-fluid matrix containing enzymes and organelles (enzyme = biological catalyst)

• Cytoskeleton– network of filaments and tubules in cytoplasm that

maintains cell shape, allows movement

Features of Prokaryotic Cells

All prokaryotic cells contain

Structure Function

Plasma Membrane Regulates flow of substances into and out of cell

Nucleoid Cytoplasmic region containing genetic material

Cytoplasm Cytosol: fluid containRibosomes& Enzymes


Other possible prokaryotic structures

Structure Function

Cell Wall Supports cellMaintains shape

Capsule Protects from dryingProtects against white blood

cells

Infolded Plasma Membranes MetabolismCell division


Other possible prokaryotic structures

Structure Function

Bacterial Flagellum Movement

Plasmid Small circular DNA Replicates independently

Applying Your Knowledge

In bacterial cells• where is the genetic material located? • which one is used for movement?• which one provides structural support for

the cell?

1. Cell Wall2. Flagellum 3. Capsule4. Plasmid5. Nucleoid

Functions of Eukaryotic Cell Features

Structure Function(s)

Plasma Membrane

1. Regulates passage of materials into and out of cell

2. Cell-Cell Recognition



Cell Wall(protists, fungi, plants)

1. Controls cell shape, protects, supports



Nucleus 1. Carrier of genetic material DNA + protein = chromatin2. Governs cell activities3. Directs cell reproduction4. Surrounded by Membrane =

nuclear envelope5. Contains nucleolus—produces

ribosomes which synthesize proteins



Rough Endoplasmic Reticulum (RER)

1. Associated ribosomes produce proteins

2. Prepares proteins for export

Smooth Endoplasmic Reticulum (SER)

1. Lipid Synthesis2. Drug detoxification3. Transport of proteins from RER


Structure Function(s)Golgi Apparatus

Collects, modifies, packages and distributes proteins and lipids from ER



Lysosome Contains digestive enzymes to digest food in protists or destroy aging organelles


Structure Function

Peroxisome Removes harmful oxidants from cells


Structure Function

Mitochondrion Captures energy from organic molecules, producing ATP

Structure Function

Chloroplast(protists, plants)

Photosynthesis: Uses light energy to produce organic molecules



Cytoskeleton 1. Maintains cell shape2. Anchors organelles and proteins3. Allows for organelle movement

and cellular movement in some cell types


Structure Function

Centriole Gives rise to basal bodies that produce cilia or flagella



Cilia and Flagella

1. Move substances across cell surface (fallopian tubes)

2. Cell movement (in sperm)


Applying Your Knowledge

A. Which organelle produces proteins that will be exported from the cell?

B. Which organelle contains digestive enzymes?

C. Which site acts as a protein packaging and distribution center?

1. Cilium2. Rough ER 3. Golgi apparatus4. Smooth ER5. Lysosome

Documents

Cell structure Mrs. Dalia Kamal Eldien Practical NO 1