Lecture 2: Cell Biology and Chemistry Refresh

What are the charges of sodium, potassium, and chloride?

sodium = Na+

Potassium = K+

Chloride = Cl -

What is responsible for the neurons electrical properties?

The maintenance of a difference in concentration of sodium, potassium, and chloride inside and outside the cell

Dendrite

cell extension that collects info from other cells

dendritic spine

small protrusions on dendrites that increase surface area

Nucleus

central structure containing the chromosome and genes

Nuclear membrane

Membrane surrounding the nucleus

Endoplasmic reticulum

Folded layers of the membrane where proteins are assembled

Mitochondrion

Structures that gather, store, and release energy

Intracellular fluid

fluid in which the cells internal structures are suspended

microtubules

tiny tubes that transport molecules and help give the cell its shape

cell membrane

membrane surrounding the cell

axon

extension that transmits information from cell body to other cells

lysosomes

sacs containing enzymes that break down wastes

Microfilaments

Threadlike fibers making up much of the cells “skeleton”

Golgi Body

Membranous structure that packages protein molecules for transport

Soma

where the nucleus lies, where the neuron's DNA is housed, and where proteins are made to be transported throughout the axon and dendrites

Ribosomes

***involved in the production of proteins***

What are the three main things you need to know about the cell membrane?

1. forms a barrier to regulate the movement of ions and water into and out of cell
2. Most of it is made of material that is impermeable to water and ions (because they are large and charged)
3. These materials can only get in through protein channels and gates on the membranes

What are the two main jobs of ion transporters?

1. Actively move ions against the concentration gradient
2. Create ion concentration gradients

What are the two main jobs of ion channels?

1. Allow ions to diffuse down concentration gradient
2. Cause selective permeability to certain ions

What is the basis for how all cells work?

The ion channels/transporters and the proteins

T/F: Genes are the blueprints for how all of the proteins of a cell are made

True

What is the next step after the proteins are made?

Make sure they end up where they need to go

Where does Gene transcription occur?

At the nucleus

What are the three important aspects of transcription?

1. DNA is a blueprints that we don’t wanna mess with so we make copies to work with
2. Transcription take the code in DNA and turns it into a copy of the form that the “processing plant” or ribosome can work with (mRNA)
3. Promoter regions of DNA are markers that transcription machinery recognizes, in order to know where to start reading and when

What is a chromosome?

Double stranded molecule of DNA

What binds with what within a chromosome?

Adenine binds with thymine. Guanine binds with cytosine

What is the process of transcription?

1. DNA uncoils to expose a gene, a sequence of nucleotide bases that codes for a particular protein
2. the gene serves as a template for transcribing a strand of mRNA
3. After modification, mRNA leaves the nucleus and comes in contact with ribosomes in the endoplasmic reticulum
4. As a ribosome moves along mRNA, it translates the bases into a specific amino acid, which becomes part of a peptide chain

What are the 5 main parts of translation?

1. Takes the code in mRNA and makes a useable protein out of it
2. Endoplasmic reticulum is studded with ribosomes that read mRNA
3. 3 nucleotides (1 codon) = 1 amino acid
4. Many amino acids together = 1 polypeptide chain (protein)
5. Proteins are coded as a 1 dimensional string, but their chemical properties cause them to fold into useful 3 dimensional figures

(A) Primary Structure

(B) Secondary Structure

(C) Tertiary Structure

(D) Quaternary Structure

(A) amino acid chains

(B) form pleated sheets or helices

(C) they fold to form a protein

(D) proteins combine to form a more complex protein

What do golgi bodies and microtubules do?

Protein packaging and shipment

What are the three important parts of protein packaging and shipment?

1. Just as important as the creation of proteins
2. Golgi bodies wrap proteins up and mark them for where they go
3. microtubules carry proteins up and down the long processes of the neuron

Explain the process of protein packaging an shipment

1. Proteins formed in the ER enter the golgi bodies, where they are wrapped in a membrane and given a shipping address
2. Each protein is attached to a motor molecule and moves along the microtubule to its destination
3. protein may be incorporated in the membrane
4. or may be excreted from the cell by exocytosis

exocytosis

the process by which cells move materials from within the cell into the extracellular fluid