Eukaryotic cell structures

Structures that are formed in bacteria’s in response to harsh conditions through process sporulation, so that they can survive many more years.

• most common spore forming bacteria genus: Bacillus and Clostridium

Endospores

Cell type that contains nucleus and membrane bound organelles

What makes eukaryotes special

Contains the cells genome surrounded by the nuclear envelope which is a double layer membrane with pores to control permeability

The nucleus

• Eukaryotic DNA structures that are linear

• Condense to form chromosomes before division

• Associated with histones

Chromatin

Area within the nucleus that is rich in rRNA and where ribosome subunits are made

The nucleolus

Made in the nucleolus by combining rRNA and ribosomal proteins. They are then exported to the cytoplasm to form the intact and active ribosome to allow for protein synthesis

Ribosome subunits

• 80S ribosomes

• Made of subunits 60S and 40S

Eukaryotic ribosomes

• 70S ribosomes

• Made of subunits 50S and 30S

Prokaryotic ribosomes

• found in the small subunit (30S) of bacterial ribosomes

• Differs between bacterial species so is used for identification, classification and phylogenetic studies

Gene for 16S rRNA

Membrane bound channels that are continuous with the nuclear membrane. 2 types: rough and smooth

The endoplasmic reticulum

• has attached ribosomes

• Major producer of glycoproteins and makes new membrane material packed into vesicles to be transported within the cell

Rough ER

• participates in lipid synthesis

• Also participates somewhat in carbohydrate metabolism

Smooth ER

stack of membranes that modify and sort the products of the ER to allow them to be secreted or travel to the right place in the cell

The Golgi apparatus

• 2 membranes, inner and outer

• Their own DNA and ribosomes

• Cristae, foldings on inner membrane for respiration and ATP production

• Matrix has enzymes for citric acid cycle

The mitochondria

• where photosynthesis occurs

• Have their own DNA and ribosomes

• Thylakoids are structures that hold chlorophyll pigments

Chloroplasts

Membrane enclosed structures that hold various digestive enzymes for the breakdown of macromolecules. Breakdown and rebuild as needed

Lysosomes

The structure that fills the cytoplasm to give the cell shape. Made of components: microfilaments, intermediate filaments, microtubules

The cytoskeleton

• subunits of actin

• Define and maintain the shape of the cell and allow for cellular movements including gliding and contraction

Microfilaments

Provide tensile strength to the cell

Intermediate filaments

• subunits of tubulin

• Help maintain cell structure, role in motility, form spindle fibers used to separate chromosomes in mitosis

Microtubules

Made of proteins and a lipid bilayer

Eukaryotic plasma membrane

Cell wall made of cellulose

Special structure of plant cells

• ex. Types of fungi

• Outer cell wall made of cellulose or chitin

Eukaryotic microorganisms special structure

• flagella and/or cilia

• Both made of microtubules surrounded by membrane

Motility organelles of eukaryotes