Prokaryotic and Eukaryotic Cells

3 domains of life

Domain bacteria, domain archaea, and domain eukarya

What are basic features of all cells?

1) Cell membrane-selective barrier

2) Chromesomes- Carry genes in form of DNA

3) Ribosomes- Synthesis proteins

4) Cytosol - Semifluid substance in which subcellular components are suspended

Characteristics of Prokaryotic cells

1) No membrane bound organelles

2) DNA is unbound in Nucleoid (no nucleus)

3) Single celled or unicellular organisms

Features of Prokaryotic Cell

1) Fimbriae

2) Nucleoid

3) Ribosomes

4) Plasma membrane

5) Cell wall

6) Glycocalyx- Outer coating

7) Flagella (sometimes)- cellular locomotion

Features of Eukaryotic Cells

1) DNA in double bound nucleus

2) Membrane bound organelles

-Perxiosomes

3) Cytoplasm between plasma membrane and nucleus

4) Much larger

Components of nucleus

-nuclear envelope is a double membrane-each layer is a lipid bilayer

-Chromatin

-Chromesome

-Nucleolus, where ribosomes are made

-Nuclear pores-ribosomes and mRNA leave

Mitochondria and Chloroplasts

Mitochondria-sites of cellular respiration, the metabolic process that uses oxygen to generate ATP

Chloroplasts-found in plants and algae, are the sites of photosynthesis

Both change energy from one form to another

Peroxisomes

-oxidative organelles bounded by a single membrane

-Produce hydrogen peroxides as a by-product and then coverts into water (neutralizing them)

-Detoxify harmful substances and break down fatty acids

-Only in eukaryotes

Cytoskeleton

-supports the cell and maintains its shape

-interacts with motor proteins to produce cell mobility

3 fibers make it up

Microtubules-thickest of the three components of the cytoskeleton

Microfilaments (actin filaments)-thinnest components

Intermediate filaments- fibers with diameters in a middle range

Centrosomes and Centrioles

-Only in animal cells

-Microtubules grow out from a centrosome near the nucleus

-Centrosome has a pair of centrioles, each with nine triplets of microtubules arranged in a ring

What is in animal cells, but not plant cells?

-Lysosomes

-Centrosomes with centrioles

-Flagella

In plant cells and not animal cells

-Vacuole

-Plasmodesmata

-Chloroplasts

-Cell wall

Function of Endoplasmic Reticulum

Rough ER-Protein synthesis and modification (many ribosomes)

Smooth ER-Lipid synthesis, Detoxification, Calcium ion storage, and Carbohydrate metabolism

Function of golgi apparatus

Modifies proteins and lipids, Sorts molecules, Packages into vesicles, Secretion (export), Forms lysosomes

-Recieves vesicles on cis side and releases them on trans side

Function of lysosomes-

Contains powerful hydrolytic enzymes that break down

Destruction of pathogens

Autophagy (“self-eating”)

Apoptosis (programmed cell death)

Function of Vacuole

Storage, Maintains turgor pressure, Waste management