* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cells - Part 2 Nucleus
Protein moonlighting wikipedia , lookup
Western blot wikipedia , lookup
Protein adsorption wikipedia , lookup
Eukaryotic transcription wikipedia , lookup
Non-coding DNA wikipedia , lookup
RNA polymerase II holoenzyme wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Polyadenylation wikipedia , lookup
Gene regulatory network wikipedia , lookup
Molecular evolution wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Biochemistry wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Two-hybrid screening wikipedia , lookup
Messenger RNA wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Non-coding RNA wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Expanded genetic code wikipedia , lookup
Point mutation wikipedia , lookup
Proteolysis wikipedia , lookup
Cell-penetrating peptide wikipedia , lookup
Endomembrane system wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Genetic code wikipedia , lookup
Gene expression wikipedia , lookup
Epitranscriptome wikipedia , lookup
Chapter 3, Part 2 – Cellular Organelles! Cells - Part 2! Cells and Related Functions! • Organelles (“little organs”)! • Cell Cycle/Cell Division (Ch. 19, pp. 394 - 398)! • DNA Replication (Ch. 21, pp. 434 - 436)! • Protein Synthesis (Ch. 21, pp 436 - 441) ! • Enzyme function (Ch. 2, pp. 31 - 32) ! 1! Nucleus! Considered “the brain of the cell”! Surrounded by double membrane! • Nuclear envelope with nuclear pores! Contains:! • DNA in chromosomes! " "Genes are instructions for building proteins! " "23 pairs of chromosomes in humans! • RNA and proteins! • Nucleolus! 2! 1! Chapter 3, Part 2 – Cellular Organelles! Nucleus " " " " " " Figure 3.13! Rough ER! ! Nucleus! Nucleolus! Nucleoplasm! Nuclear! envelope! Chromatin! Nuclear! pores! 3! Nucleolus" " " " "! Found within the nucleus! Does not have its own membrane! Contains:! • DNA + rRNA + ribosomal proteins, enzymes! • Ribosomes are assembled here! Nucleus! (Martini 2004)! Nucleolus! 4! 2! Chapter 3, Part 2 – Cellular Organelles! Ribosomes! Sites of protein synthesis" Composed of a large and a small ribosomal subunit! Contain ribosomal RNA (rRNA) + protein! • Free ribosomes: suspended in cytoplasm! • Fixed (bound) ribosomes: attached to endoplasmic reticulum! 5! Ribosomes " " " " " Figure 21.7! 6! 3! Chapter 3, Part 2 – Cellular Organelles! Endoplasmic Reticulum! Composed of intracellular membranes! Two types have different functions: ! • Rough ER (RER) - contains ribosomes ! • Smooth ER (SER) - no ribosomes! 7! Rough Endoplasmic Reticulum Figure 3.15a! 8! 4! Chapter 3, Part 2 – Cellular Organelles! Rough ER – General Functions! Has ribosomes attached" Make proteins for…! 1. Secretion from cell! 2. Inclusion in cell membranes! 3. Inclusion in lysosomes! Other functions:! • Intracellular transport! • Temporary storage! 9! Smooth ER – General Functions! No ribosomes attached" ! 1. Makes vesicles that transport proteins to Golgi apparatus! 2. Synthesizes lipids! 3. Storage area! 4. Detoxification reactions in the liver! 10! 5! Chapter 3, Part 2 – Cellular Organelles! Golgi Apparatus Functions! Acts like the Post Office:! • Sorts, packages, delivers molecules! Forms secretory vesicles! • Discharged by exocytosis! Forms new membrane components! Forms lysosomes! 11! Golgi Apparatus " " " " Figure 3.17! 12! 6! Chapter 3, Part 2 – Cellular Organelles! Lysosomes! Lysosomes! Contain digestive enzymes used in:! • Digestion following phagocytosis/ endocytosis! • Autophagy (recycling)! 13! Lysosome Functions " " " Figure 3.17! 14! 7! Chapter 3, Part 2 – Cellular Organelles! Mitochondria " " " " " Figure 3.19! Responsible for ATP production through aerobic respiration (aerobic???)! Matrix = fluid contents of mitochondria! Cristae = folds in inner membrane! 15! 16! 8! Chapter 3, Part 2 – Cellular Organelles! Chromosomes, Cell Division:! "Chapter 19: pp. 394 – 398! DNA Replication, Protein Synthesis! "Chapter 21: pp. 434 - 441! 17! Nucleus Contains Genes on Chromosomes! Surrounded by a nuclear envelope (a double membrane)! Communicates with cytoplasm through nuclear pores in the envelope! Contents of the nucleus:! • Enzymes, nucleotides (DNA, RNA), ions, etc.! • One or more nucleoli! • Chromosomes! 18! 9! Chapter 3, Part 2 – Cellular Organelles! Cell Division! Cell division is the reproduction of cells! "1. Mitosis is the nuclear division of somatic cells! "2. Meiosis produces sex cells! • We’ll cover this with Reproduction.! 19! Cell Cycle " " " " " Figure 19.2! Withdrawal from cell cycle! Mitosis! 20! 10! Chapter 3, Part 2 – Cellular Organelles! DNA Replication " " " " Figure 21.2! A is complementary to T! G is complementary to C! ! It’s that simple (for this class). Really!! ! DNA polymerase (an enzyme) knows how to do this.! ! How does this base pairing scheme differ from that seen in RNA??! 21! The Genetic Code for Protein Synthesis! A triplet code on DNA (and later, on RNA)! • Three nitrogenous bases in sequence along a DNA strand code for one amino acid.! • The information is transcribed to mRNA and carried to the ribosome.! A gene contains all the triplets needed to code for a specific polypeptide! • DNA contains code" • mRNA contains codon" 22! • tRNA contains anticodon" 11! Chapter 3, Part 2 – Cellular Organelles! The Genetic Code! mRNA Codons" Figure 21.5! ! Codon: Three bases in sequence specify that a particular amino acid will be added to a growing protein during protein synthesis! 23! Protein Synthesis Overview! transcription! DNA! translation! RNA! Protein! Transcription:! • Information stays in the same language (A language of base pair sequences)! Translation:! • Information is translated from base pair sequences to amino acid sequences (A language of amino acids)! 24! 12! Chapter 3, Part 2 – Cellular Organelles! Making Proteins Requires: " " (1 of 2)! 1. Instructions:! • Genes (code) on DNA in the nucleus! 2. An assembly site:! • Ribosomes! "rRNA (ribosomal RNA) + proteins located in the cytoplasm! 3. Messenger - “Federal Express”:! • mRNA (messenger RNA) carries instructions (codon) from the nucleus to ribosomes in cytoplasm! Making Protein Requires:" " " 25! "(2 of 2)! 4. Raw materials:! • Amino acids in cytoplasm! 5. Transport of raw materials to assembly site:! • tRNA (transfer RNA) contains anticodon and carries amino acids to the assembly site (ribosome)! 26! 13! Chapter 3, Part 2 – Cellular Organelles! Transcription! Gene activation begins with RNA polymerase binding to the gene (DNA)! ! Transcription is the formation of mRNA from DNA! • mRNA carries instructions from the nucleus to the ribosome in the cytoplasm! 27! Transcription " " " " " Figure 21.3! 28! 14! Chapter 3, Part 2 – Cellular Organelles! Translation is the Formation of a Polypeptide! A functional polypeptide is constructed from information contained in mRNA codons" The sequence of codons in mRNA determines the the sequence of amino acids in a polypeptide! Complementary base pairing with anticodons (tRNA) provides the amino acids in the correct sequence! " "A is complementary to U! " "C is complementary to G! 29! Transfer RNA (tRNA) " " " Figure 21.5! amino acid! Transfer RNA - carries amino! acids to the ribosome! AAA - anticodon on tRNA! UUU - codon on mRNA! 30! 15! Chapter 3, Part 2 – Cellular Organelles! Translation Process - 1 " " "Figure 21-8a! Step 1:! Small subunit binds! mRNA at start sequence! site! 31! Translation Process – 2 " " " Figure 21.8! Step 2:! ! • tRNA with with ! complementary ! anticodon binds ! START codon! ! • Ribosomal subunits ! unite! 32! 16! Chapter 3, Part 2 – Cellular Organelles! Translation Process – 3 " " " Figure 21.9! 33! Translation Process – 4 " " "Figure 21.11! Termination of translation process! 34! 17! Chapter 3, Part 2 – Cellular Organelles! 35! 36! 18! Chapter 3, Part 2 – Cellular Organelles! Cell Differentiation! The process of specialization! • Cells take a “career path”! Results from inactivation of particular genes! Produces populations of cells with limited capabilities! Differentiated cells form tissues! 37! Protein Synthesis Animations! Protein synthesis animation #1! • https://www.biostudio.com/ demo_freeman_protein_synthesis.htm! Protein synthesis animation #2! • https://www.youtube.com/watch? v=Ikq9AcBcohA! If you find a really useful one on the web, please send me the link! 38! 19! Chapter 3, Part 2 – Cellular Organelles! Enzymes are Biochemical Catalysts! Enzymes:! 1. Speed up chemical reactions that would normally occur! 2. Not permanently changed by the reaction! 3. Work in both directions! " "A + B ↔ A-B! 4. Are selective/specific! 5. Work best in certain (optimal) environment "Temperature, pH, salinity, etc……! 6. Can be saturated! 39! Enzymes! Figure 2.25! 40! 20!