Download Free Medical DNA RNA and PROTEINS PowerPoint Presentation

DNA RNA and PROTEINS PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : Check out this medical presentation on Genetics, which is titled "DNA, RNA & PROTEINS", to learn about DNA, RNA and PROTEINS, the molecules of life.

Tags : Genetics, DNA, RNA, PROTEINS, molecules

Published on : Aug 29, 2021 | Views : 2697 | Downloads : 2

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

DNA, RNA & PROTEINS The molecules of life
Slide 2-

DNA Deoxyribonucleic Acid (DNA) is the blueprint for life:
Slide 3-

DNA structure DNA is a polymer of nucleotides Each nucleotide composed of _________________ _________________ _________________
Slide 4-

Four DNA bases Four kinds of nitrogenous bases: Purine bases Pyrimidine bases
Slide 5-

DNA: Complimentary base pairing Adenine pairs with ________ A Cytosine pairs with _________ C
Slide 6-

DNA STRUCTURE DNA is a ________ helix Discovered by Watson and Crick
Slide 7-

DNA REPLICATION (in the nucleus)
Slide 8-

DNA Replication First an enzyme DNA topoisomerase untangles the coils Next: Enzymes called “Helicase” “unzip” the DNA molecule exposing both strands nitrogenous bases. The DNA is separated into two strands.
Slide 9-

DNA Replication Then: (enzyme) DNA polymerase pairs the bases A-T and G-C. DNA Polymerase checks work and corrects mistakes …. Nucleotides are paired DNA ligase (enzyme) follows behind and bonds the nucleotides together. Two strands of DNA are created.
Slide 10-

DNA Replication The process is fast and accurate an error occurs in only about one of a billion nucleotides.
Slide 11-

DNA replication begins at specific sites called origins of replication. The copying proceeds outward in both directions, creating replication "bubbles". The parent DNA strands open up as daughter strands grow on both sides of each bubble.
Slide 12-

A eukaryotic DNA molecule has many origins where replication can start at the same time. This shortens the total time to copy all the DNA. Eventually, all the bubbles merge End product: two double-stranded DNA molecules, each with one new and one old strand.
Slide 13-

DNA replication occurs before a cell divides, ensuring that the cells in a multicellular organism all carry the same genetic information. It is also the mechanism for producing the DNA copies that offspring inherit from parents during reproduction.
Slide 14-

DNA replication The resulting double-stranded DNA molecules are identical; proofreading and error-checking mechanisms exist
Slide 15-

RNA structure and synthesis RNA: RIBONUCLEIC ACID Is very similar to DNA (repeating subunits, nucleotides). Difference between RNA and DNA: 1. Each nucleotide contains a different sugar: RIBOSE instead of deoxyribose. 2. Bases are A, G, C, and U (URACIL) A pairs with U; G pairs with C
Slide 16-

RNA 3. RNA is single stranded and shorter
Slide 17-

CENTRAL DOGMA DNA RNA Proteins 3 different RNA molecules involved in protein synthesis: mRNA (messenger RNA) rRNA (ribosomal RNA tRNA (transfer RNA) transcription translation
Slide 18-

PROTEIN SYTNESIS 1 step: Transcription occurs in the nucleus 2 step: Translation occurs in the cytoplasm
Slide 19-

1st step Transcription: DNA  RNA Transcription occurs in the nucleus First: DNA unwinds in a section Next: mRNA (messenger RNA) is formed by base pairing with the parent strand of DNA. This begins transcription. Then: mRNA carries the message about what type of protein to make from the DNA in the nucleus to the ribosome
Slide 20-

Transcription Once mRNA is formed, enzymes in the nucleus remove the Introns (noncoding message) and leave the Exons (good message)
Slide 21-

The Genetic Code Each 3 consecutive bases on the mRNA is a code word, CODON, that specifies an amino acid. The genetic code consists of 64 codons, but only 61 code amino acids. Three codons act as signal to stop the process One codon, AUG, codes for methionine, and is also the Start signal for translation.
Slide 22-

2nd step Translation: RNA  Protein Translation: synthesizing a code from amino acids, according to the sequences of the nucleotides in mRNA. Occurs at the ribosome, in cytoplasm of cell Ribosomal RNA, rRNA, is needed for protein synthesis – helps mRNA bind to the ribosome tRNA, brings specific amino acids to the ribosome to be assembled as proteins.
Slide 23-

Translation Ribosomes are the sites of ______________
Slide 24-

Transfer RNA (tRNA) Transport molecule that carries specific amino acid to a ribosome Each tRNA recognizes the correct codon on the mRNA molecule
Slide 25-

Translation
Slide 26-

Steps in Translation mRNA leaves the nucleus and migrates to ribosome mRNA binds to small ribosomal subunit tRNA brings an amino acid to the ribosome, where anticodon on the tRNA binds to the codon of the mRNA The amino acid bonds to its adjoining amino acid to form a growing polypeptide molecule The tRNA without the amino acid is released from the ribosome Other tRNA’s bring amino acids to the ribosome to complete the protein molecule
Slide 27-

Protein translation
Slide 28-

Protein synthesis Occurs in the cytoplasm of the cell
Slide 29-

Summary:
Slide 30-

Important Both DNA and RNA have a direction: one end is the 3’ the other is the 5’ end. Thus, codons are read in one direction only. Also, note there is redundancy in the genetic code: the different sequences can specify for the same amino acid. Example: _______________= Leucine
Slide 31-

When things go wrong… Mutations: changes in the DNA sequence, that may be passed along to future generations. Point mutations: a single base substitution THE CAT SAW THE RAT THE CAT SAW THE HAT Deletion: a small DNA segment is lost Insertion: a segment of DNA is added Frame-shift mutation: modification of the reading frame after a deletion or insertion, resulting in all codons downstreams being different.
Slide 32-

Somatic Mutations ___________ mutations: occur in body cells, or cells that do not lead to gametes. Somatic mutations that occur in leaves, roots or stems are usually not passed on to future generations… UNLESS the plant reproduces ____________