Ingenuity Honor’s Biology December 3rd, Monday Baltimore Polytechnic Institute Ingenuity Honor’s Biology December 3rd, Monday Unit 3: Cells: Nucleus & Endoplasmic reticulum, Golgi apparatus and vesicles Insong James Lee, Ph.D.

Unit 3: Cells: Nucleus & Endoplasmic reticulum, December 3rd, Monday Learning objectives: Briefly describe the nucleus. What are its functions? Describe the structure and functions of organelles involved with protein production in cells, including rough ER, smooth ER, ribosomes, Golgi apparatus, and vesicles. What is the ribosome made up of? What is its function? What is the difference between the smooth and rough endoplasmic reticulum. Unit 3: Cells: Nucleus & Endoplasmic reticulum, Golgi apparatus and vesicles

Unit 3: Cells: Nucleus & Endoplasmic reticulum, Golgi apparatus and vesicles Topic slides Nucleus 4-15 2. Logic break. 16 Endomembrane system 17-30 (endoplasmic reticulum, golgi apparatus, vesicles)

Nucleus slides 5-15

Should we be afraid of the clones?

The Nucleus The nucleus is a small sphere that holds almost all of a eukaryotic cell’s DNA.

Structure & Function of Nucleus Structure: Spherical lipid membrane bound organelle (like cell membrane) that contains DNA. Functions: Stores DNA, controls cell activity

The nucleus is found ONLY in EUKARYOTIC cells.

Dolly the Sheep Dolly was the first clone of an adult mammal ever made. Dolly was born in 1997, she died a few years later, younger than usual for a sheep. So what does a cloned sheep have to do with a cell nucleus?

When adult animals are cloned, it is by adding a nucleus from a cell to a new egg cell without a nucleus

How to Make a Sheep: The Point: Change the nucleus = change the organism (remove Nucleus) (to get the new nucleus into the enucleated cell) Ewe: female sheep

nuclear envelope: A lipid bilayer that surrounds the nucleus nuclear pores: openings in the nuclear envelope

Most of the inside of a nucleus is made up of chromatin, which is a mix of DNA and proteins

The nucleolus is a small dark part inside a nucleus where ribosomes are made.

Find those parts: Nuclear Envelope Nuclear Pores Chromatin Nucleolus

Logic break TASK: Six classmates raced one another on the playground during recess. Use a matrix (grid) to find out who came in first, second, third, fourth, fifth, and sixth. 1. Alice crossed the finished line immediately after Austin. 2. Aaron finished right between Allen and Abby. 3. Adam won the race. 4. Aaron came in right after the boy who finished second. 5. Austin saw four people finish before him. 6. Allen did not finish fourth.

Endomembrane system (in the cytoplasm) slides 18-30

General Cell Terminology Everything between the nucleus and the cell membrane is called CYTOPLASM. CYTOPLASM is: All of the organelles like mitochondria, etc. The CYTOSOL, which is the aqueous solution everything else floats around in

The Endomembrane system The endomembrane system is a series of folded lipid membranes where protein production takes place. It includes: The nuclear envelope The rough and smooth endoplasmic reticulum The Golgi bodies Vesicles PROKARYOTES have NO INTERNAL MEMBRANES. Protein production occurs in the cytoplasm

The Endoplasmic Reticulum Structure: The endoplasmic reticulum is a large series of folded membranes attached to the outside of the nucleus. Function: Freshly made proteins travel into the lumen of the ER and gets folded and processed within the ER.

Two Parts of the ER The first part has RIBOSOMES attached to it, and is therefore called the ROUGH endoplasmic reticulum. The second part has no ribosomes and is called the SMOOTH endoplasmic reticulum. The function of the smooth ER is to produce new lipids for vesicles and membranes.

About those SUPER IMPORTANT ribosomes… Very important function: RIBOSOMES MAKE PROTEINS! Structure: Made up of many proteins and three pieces of rRNA combined

More on Ribosomes in the Future… We’ll learn more about how ribosomes make proteins when we study molecular genetics. The ribosome basics: Made up of rRNA and proteins. millions per cell. Use the information in mRNA to build proteins from amino acids. Found in all cell types.

Rough then Smooth The rough ER is where proteins are built. The smooth ER has several functions Most importantly: Lipid synthesis (for membranes) Home to many enzymes.

Golgi apparatus Structure: folded membranes Function: Proteins are modified folded into correct conformations & quarternary structures Modified chemically Addition of chemical groups (e.g. heme in hemoglobin, etc.) Modified amino acids label proteins so they get delivered to the right places. What might they be labeled with?

Protein Production Smooth Endoplasmic Reticulum Transport Vesicle Amino Acids Rough Endoplasmic Reticulum Outgoing Transport Vesicles Golgi Apparatus mRNA Ribosome Transport Vesicles Nucleus (DNA)