Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure –...

28
Prokaryotic and Eukaryotic Cellular Structure

Transcript of Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure –...

Page 1: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Prokaryotic and Eukaryotic Cellular Structure

Page 2: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Prokaryotic & Eukaryotic Cells: An Overview

Prokaryotes

Do not have membrane surrounding

their DNA

lack a nucleus

Lack various internal structures bound with phospholipid membranes

Are small, ~1.0 µm in diameter

Have a simple structure

Composed of bacteria and archaea

Page 3: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Prokaryotic & Eukaryotic Cells: An Overview

Eukaryotes

Have membrane surrounding their

DNA

Have a nucleus

Have internal membrane-bound

organelles

Are larger, 10-100 µm in diameter

Have more complex structure

Composed of algae, protozoa,

fungi, animals, and plants

Page 4: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Prokaryotic & Eukaryotic Cells: An Overview

[INSERT FIGURE 3.1]

Page 5: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately
Page 6: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Prokaryotic Cell Membrane

• Structure

– Referred to as phospholipid bilayer; composed of lipids and associated proteins

– Approximately half composed of proteins that act as recognition proteins, enzymes, receptors, carriers, or channels

• Integral proteins

• Peripheral proteins

• Glycoproteins

– Fluid mosaic model describes current understanding of membrane structure

Page 7: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Cell Membrane

Membranes contain a

hydrophilic and

hydrophobic side

Composed of many

different types of

proteins

Proteins in the lipid

bilayer move freely

within the membrane

Page 8: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Cell Membrane

Thin pliable lipid and protein envelope

that defines a cell.

Phospholipid bilayer

Functions:

• Regulates nutrient and water

intake

• Regulates waste removal

• Site of prokaryotic respiration

• Site of prokaryotic flagella

attachment

• Involved in the distribution of

genetic material during binary

fission

Page 9: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Bacterial Appendages Flagella

Structures of locomotion

Originate in the plasma

membrane

In bacteria rotate like a

propellar

Many different

arrangements

Page 10: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

External Structures of Prokaryotic Cells

• Flagella

– Are responsible for

movement

– Have long structures that

extend beyond cell surface

– Are not present on all

prokaryotes

Page 11: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

External Structures of Prokaryotic Cells

Flagella

Structure Composed of filament, hook,

and basal body

Flagellin protein (filament) deposited in a helix at the lengthening tip

Base of filament inserts into hook

Basal body anchors filament and hook to cell wall by a rod and a series of either two or four rings of integral proteins

Filament capable of rotating 360º

Page 12: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Bacterial Appendages Arrangements of Flagella

A. Monotrichous

B. Lophotrichous

C. Amphitrichous

D. Peritrichous

Page 13: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

5. Mesosome

Mesosomes - invagination of the

plasma membrane that increases

the surfaces area of the plasma

membrane during binary fission.

The mesosome also serves as a

site for the attachment and

distribution of genetic material

during binary fission.

Page 14: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Inclusion Bodies

6. gas vacuoles - storage of metabolic gases such as methane or hydrogen

gas. The gas vacuoles help in the buoyancy of the cell and aids in it

motility.

7. ribosomes - responsible for the synthesis of proteins.

8. nucleoid material - the genetic material of bacteria, which usually is balled

up in the cell. During binary fission the nucleoid material unravels within the

cell in order to be copied and distributed to the daughter cells.

9. Plasmid - small fragments of self-replicating extrachromosomal DNA that

codes for the resistance to antibiotics or for the productions of a specific

metabolite, i.e. toxins, pigments. These plasmids may be transferred from

one bacterial cell to another by the F-pili.

Page 15: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Inclusion Bodies

9. Plasmid - small fragments of self-replicating extrachromosomal DNA that

codes for the resistance to antibiotics or for the productions of a specific

metabolite, i.e. toxins, pigments. These plasmids may be transferred from

one bacterial cell to another by the F-pili.

Page 16: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Membranous Organelles

Nucleus Often largest organelle in cell

Contains most of the cell’s DNA

Semi-liquid portion called nucleoplasm

One or more nucleoli present in nucleoplasm; RNA synthesized in nucleoli

Nucleoplasm contains chromatin – masses of DNA associated with histones

Surrounded by nuclear envelope – double membrane composed of two phospholipid bilayers

Nuclear envelope contains nuclear pores

Page 17: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Nucleus - double membraned

organelle that houses the genetic

material of cell.

Nuclear membrane contains

numerous pores through which

proteins and RNA can move.

Page 18: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Membranous Organelles

Endoplasmic reticulum

Netlike arrangement of flattened, hollow tubules continuous with nuclear envelope

Functions as transport system

Two forms

Smooth endoplasmic reticulum (SER) – plays role in lipid synthesis

Rough endoplasmic reticulum (RER) – ribosomes attached to its outer surface; transports proteins produced by ribosomes

Page 19: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Endoplasmic reticulum - network of

cytoplasmic membranes where

lipids and proteins are produced.

Smooth ER - synthesis of lipids

Rough ER - associated with

ribosomes and is responsible for

the synthesis of proteins.

.

Page 20: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Membranous Organelles

Golgi body

Receives, processes, and packages large molecules for export from cell

Packages molecules in secretory vesicles that fuse with cytoplasmic membrane

Composed of flattened hollow sacs surrounded by phospholipid bilayer

Not in all eukaryotic cells

Page 21: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

Golgi apparatus (dictyosome) is

associated with the ER.

It modifies and packages the lipids

and proteins manufactured by the

ER and places them in vesicles for

cellular use.

Page 22: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

• Membranous Organelles

– Lysosomes, peroxisomes,vacuoles,

and vesicles

• Store and transfer chemicals

within cells

• May store nutrients in cell

• Lysosomes contain catabolic

enzymes

• Peroxisomes contain enzymes

that degrade poisonous wastes

Page 23: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

• Membranous

Organelles

– Mitochondria

• Have two membranes

composed of phospholipid

bilayer

• Produce most of cell’s

ATP

• Interior matrix contains

70S ribosomes and

circular molecule of DNA

Page 24: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Intracellular Structures of Eukaryotic Organisms (organelles)

mitochondria - involved in the

production of chemical energy in

the form of ATP.

Consist of convoluted inner

membrane and outer membrane.

Invaginations are called cristae and

contain enzymes used to synthesis

ATP.

All respiratory enzymes are located

in the inner membrane of the

mitochondria.

Page 25: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Cytoplasm of Eukaryotes

• Membranous

Organelles

– Chloroplasts

• Light-harvesting structures

found in photosynthetic

eukaryotes

• Have two phospholipid

bilayer membranes and

DNA

• Have 70S ribosomes

Page 26: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

• Endosymbiotic Theory

– Eukaryotes formed from union of small aerobic prokaryotes with larger anaerobic prokaryotes

– smaller prokaryotes became internal parasites

• Parasites lost ability to exist independently; retained portion of DNA, ribosomes, and cytoplasmic membranes

• Larger cell became dependent on parasites for aerobic ATP production

• Aerobic prokaryotes evolved into mitochondria

• Similar scenario for origin of chloroplasts

– Not universally accepted

Cytoplasm of Eukaryotes

Page 27: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Cytoplasm of Eukaryotes

[INSERT TABLE 3.5]

Page 28: Prokaryotic and Eukaryotic Cellular Structure · Prokaryotic Cell Membrane • Structure – Referred to as phospholipid bilayer; composed of lipids and associated proteins – Approximately

Cytoplasm of Eukaryotes

[INSERT TABLE 3.4]