RNA Protein Synthesis Lecture How are babies made

RNA & Protein Synthesis Lecture

How are babies made? 쓰 지마. �Meiosis �Gametes �Sex/fertilization �Zygote �DNA Replication, Cell Division / Mitosis �“Growth” (new cells mitosis)

How are cells / bodies built? �DNA Replication just makes more DNA. �Proteins…

What are proteins and what do they do? Reading Activity: �Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs. �Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determines each protein’s unique 3 -dimensional structure and its specific function.

Proteins can be described according to their large range of functions in the body, listed in alphabetical order: Function Examples of protein functions Description Example Antibody Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. Enzymes carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA. Phenylalanine hydroxylase Messenger proteins, such as some types of hormones, transmit signals to coordinate biological processes between different cells, tissues, and organs. Structural component These proteins provide structure and support for cells. On a larger scale, they also allow the body to move. Transport/storage These proteins bind and carry atoms and small molecules within cells and throughout the body. Muscle fiber protein: Ferritin

How are proteins made? 쓰 세요: �DNA carries master plan �Plan is read & rewritten into a blueprint (sequence of bases code) �Blueprint (m. RNA) instructs builders �Amino acids linked according to codes from Blueprint Proteins built!

RNA Structure �Ribonucleic Acid: Like DNA Unlike DNA Long chain of nucleotides No Thymine (no “T” base) RNA Nucleotides = sugar, phosphate, nitrogen base Sugar is ribose, not deoxyribose Copied from DNA Single-stranded

3 Types of RNA �Messenger RNA (m. RNA) �Ribosomal RNA (r. RNA) �Transfer RNA (t. RNA)

Messenger RNA (m. RNA) 1. Serve as “messengers” from DNA 2. Carry copies of instructions (blueprints) out of the nucleus 3. Coded to assemble amino acids into protein chains (polypeptides)

Ribosomal RNA (r. RNA) �Ribosomes are the machines that read m. RNA and construct polypeptides (proteins) from amino acids. �Ribosomes are comprised of two subunits. �Made of r. RNA and proteins.

Transfer RNA (t. RNA) �t. RNA: Carries & transfers each amino acid to ribosome as coded by m. RNA.

Transcription �RNA Polymerase (an enzyme) binds to DNA and separates strands. �Then uses one strand of DNA to assemble a single-stranded m. RNA molecule.

Transcription �Results in a singlestranded messenger RNA (m. RNA) which carries the code for building proteins out of the nucleus to ribosomes.

�m. RNA

Keep to the CODE! �m. RNA transcription �No Thymine in RNA base sequences:

Uracil in RNA base sequences: �In DNA: A T & G C �In RNA: A U & G C �U = Uracil �Messenger RNA (m. RNA) strand might read: �AAUGCCUAC

Practice: Transcribe DNA to m. RNA �You are RNA Polymerase (the enzyme). �DNA: TTACGGATG �RNA: AAUGCCUAC �DNA: CCGTTCATG �RNA: GGCAAGUAC �DNA: GATGGGATA �RNA: CUACCCUAU

The Genetic Code �DNA: TTACGGATG �RNA: AAUGCCUAC �Each set of three bases corresponds with a specific amino acid. �Each triplet is called a codon. �AAU – GCC – UAC AAU = Asparagine GCC = Alanine UAC = Tyrosine

Translation is… �the decoding of an m. RNA message into a polypeptide (protein) chain. �Again, each t. RNA carries one amino acid �t. RNA has an RNA anticodon corresponding & bonding to each m. RNA codon �m. RNA: CUA-CCC-UAU �t. RNA: GAU-GGG-AUA

Translation uses all three types of RNA m. RNA (messenger copies from DNA) binds with a ribosome (r. RNA), which is the machine that builds polypeptides when t. RNA transfers amino acids by matching its anticodon to the m. RNA codon.

Translation �m. RNA message: �UUCAUCGUACGC �Amino acids: �____

Transcription to Translation �DNA in the nucleus: �CCGAAGTTCATG �m. RNA brings: �GGCUUCAAGUAC �…to ribosome �t. RNA brings… �Amino acids: �Gly-Phe-Lys-Tyr �…forming part of a protein.