NRSG 205 Lecture 4 Part 2 - Eukaryotes

What 3 structures do prokaryotes have that eukaryotes SOMETIMES have?

1. Flagella

2. Cell Wall

3. Glycocalyx

4 structures that ALL cells possess

1. Plasma membrane

2. Cytoplasm

3. Nucleic acid (RNA or DNA)

4. Ribosomes

What size ribosomes do eukaryotic cells possess?

80S

Endosymbiotic theory

• A smaller prokaryote was engulfed by a large prokaryote, which gave rise to eukaryotes

• That smaller prokaryote eventually evolved into mitochondria

2 motility structures in eukaryotes

1. Flagella

2. Cilia

Flagella movement in eukaryotes

move in wave-like motion

Cilia

short hair-like structures that protrude on the surface of the cell and push the cell forward against surfaces

Which organisms have a cell wall made of cellulose?

1. Algae

2. Plants

3. Some fungi

Most fungi have a cell wall made of _______

chitin

Yeast cells have a cell wall made of _________ and __________

glucan, mannan

Are yeast cells unicellular or multicellular?

Unicellular

Cell wall in animal cells

Animal cells do not have a cell wall, but they do have glycocalyx

2 functions of glycocalyx in animal cells

1. Strengthens cell

2. Provides attachment to surfaces

2 qualities of the plasma membrane in both prokaryotes and eukaryotes

1. Phospholipid bilayer

2. Integral membrane proteins

2 qualities of the plasma membrane in only eukaryotes

1. Contains carbohydrates attached to proteins

2. Sterols

Example of a sterol in plasma membrane of eukaryotes

cholesterol - gives rigidity to the cell

Which type of prokaryote has sterols?

Myoplasmas (bacteria) do not have a cell wall, but have sterols

Endocytosis

form of active transport that brings substances into the cell

3 types of endocytosis

1. Phagocytosis

2. Pinocytosis

3. Receptor-mediated endocytosis

Phagocytosis

endocytosis of large substances; cell eating

Pinocytosis

endocytosis of smaller substances; cell drinking

Receptor-mediated endocytosis

involves a ligand binding to a receptor, then the ligand is taken up into the vesicle

Cytoplasm (eukaryotes)

Organelles, ribosomes, cytoskeleton, and more float within the cytoplasm

Endomembrane system

the system of membrane-bound organelles

7 endomembrane system organelles

1. Nucleus

2. Nuclear envelope

3. Endoplasmic reticulum (rough and smooth)

4. Golgi apparatus

5. Lysosome

6. Vacuole

7. Vesicles

2 functions of the nucleus

1. Houses DNA

2. Separates transcription from translation

Nuclear envelope

double membrane that surrounds the nucleus

What differentiates the rough vs. smooth endoplasmic reticulums?

• Rough ER is covered with ribosomes

• Smooth ER is not covered with ribosomes

Rough ER function

Protein synthesis and transport

2 functions of the smooth ER

1. Lipid synthesis

2. Detoxification

4 functions of the golgi apparatus

1. Processes proteins

2. Helps synthesize membranes

3. Protein secretion

4. “Tells” proteins their final destination

Side of the golgi closest to the nucleus

Cis golgi

Side of the golgi farthest from the nucleus

Trans golgi

Which side of the golgi do proteins enter, and which side do they exit?

Enter the cis side, exit the trans side

Proteins that are ____________________ MUST go through the golgi apparatus

secreted through exocytosis

Lysosome

 formed from the golgi apparatus and contains digestive enzymes to break down large molecules

Lysosome specific function

Breaks down non-functional substances in the cell

Vacuole

erived from the golgi apparatus or endocytosis and is responsible for storage

Plant vacuole function

Filled with water in plants and provides rigidity to the cell

Vesicles function

 allow for communication between the organelles

2 types of ribosomes

• Bound ribosomes (bound to rough ER)

• Free ribosomes (floating in the cytoplasm)

Mitochondria function

site of ATP synthesis

4 properties of mitochondria that confirm the endosymbiont theory

1. Self-replicating

2. Make their proteins using 70S ribosomes

3. Contain their own circular DNA

4. Multiply through binary fission

Chloroplast function

site of photosynthesis

Which types of cells are chloroplasts found in?

1. Plants

2. Some algae

What substance allows for photosynthesis in chloroplasts?

Chlorophyll

3 properties of chloroplasts that confirm the endosymbiont theory

1. Contain 70S ribosomes

2. Contain their own DNA

3. Self-replicating

What enzyme do peroxisomes contain?

Catalase

Catalase function

breaks down hydrogen peroxide into water and oxygen

2 functions of peroxisomes

1. Oxidizes organic compounds

2. Hydrogen peroxide is toxic and is produced through oxidation, so peroxisome converts it using its catalase

Centrosome

perpendicular structures that are involved in the synthesis of microtubules

3 cytoskeletal elements (smallest to largest)

1. Actin microfilaments

2. Intermediate filaments

3. Microtubules

Microtubules location in cell

extend from the pericentriolar region

3 functions of microtubules

1. Move chromosomes to the right place in mitosis

2. Provide structure to cell

3. Transport of vesicles in the cell (long distance)

Actin microfilament location in cell

Found near periphery of the cell

2 functions of actin microfilaments

1. Allows things to move on the surface of the cell by changing the shape

2. Aid in transport (short)

Intermediate filaments location in cell

Found near nucleus

Intermediate filaments function

create a scaffold in which the nucleus sites