MOLECULES TO CELL - NUCLEUS

What is the nucleus?

Contains the genetic material (DNA), wrapped around proteins to form chromatin.

The nucleus is composed of chromosomes, nucleolus and nuclear envelope

What are chromosomes?

Contains DNA, packaged with proteins called chromatin.

Nucleolus

Area rich in ribosomal RNA.

Nuclear Envelope

Two phospholipid bi-layers form the nuclear membrane (contains nuclear pores - allowing entry/exit of molecules).

DNA

DNA is a double-stranded linear molecule. It contains hydrogen bonded base pairs

What happens during DNA Replication?

If double helix unwinds, new copies of each individual DNA strand can be made.

What happens during transcription?

Small sequences of the larger DNA molecules (genes), can be transcribed into more unstable single stranded RNA.

RNA

3 types used in protein synthesis: mRNA, rRNA and tRNA.

What is mRNA?

Temporary copy of gene.

What is rRNA?

Forms ribosome.

What is tRNA?

Decodes info on a mRNA molecule and translates into the amino acid language of proteins.

What are ribosomes?

Ribsomes are a cell organelle found in all cells and make proteins.

What is Protein Synthesis?

The process of making proteins from transcription and translation.

Compartmentalization

The cytoplasmic structure is complicated with specific sites and structures specialized for distinct functions.

Protein Variety

Variety of proteins can be made from transcription and translation.

Messenger RNA

Leaves the nucleus with the instructions for the synthesis of a specific protein.

Ribosome Structure

A complex of Ribosomal RNA and proteins which interact with mRNA and tRNAs to make Proteins.

Eukaryotes

Organisms whose cells have a nucleus enclosed within membranes.

Prokaryotes

Organisms whose cells lack a nucleus.