NURS1110- Lecture 2 2023.pptx

Biochemistry NURS 1110 Lecture 2 – Cell Function DNA/RNA Andrew S. Dhanoo BSc., RPT, PhD. (candidate) We will begin at 8:10am… School of Nursing, Fac. Med Sci. UWI. Dept. Life Sciences, Fac. of Sci. and Tech....

Biochemistry NURS 1110 Lecture 2 – Cell Function DNA/RNA Andrew S. Dhanoo BSc., RPT, PhD. (candidate) We will begin at 8:10am… School of Nursing, Fac. Med Sci. UWI. Dept. Life Sciences, Fac. of Sci. and Tech. UWI. Diabetes Association of Trinidad and Tobago Food Advisory Committee – Ministry of Health Trinidad and Tobago NCD Alliance Contact Information Email: [email protected] NB: When emailing, please include the following : This course’s code (NURS 1110) Your Full name Your Student ID number Text Book Handbook of Applied Biochemistry, Nutrition and Dietetics for Nursing and Allied Health Students: For Nursing and Allied Health Students By: Shivananda Nayak B (Author) Select if you would like a textbook in the attendee register.  Course Outline Credits: 3 Class Schedule: Friday – 8 am - 12 noon (ZOOM – 1st Lecture) Course Delivery: Lectures, with in-class demonstrations Course Assessment: 1. In-course Exams: 25 % - Incourse 1 : 8% (week 4) - Incourse 2 : 8% (week 8) - Incourse 3 : 9% (week 13) 2. Group Project: 15 % - Outline/Lit. Review: 3% (week 6) - Oral Presentation: 6% (week 11) - Academic Poster: 6% (week 12) 3. Final Exam: 60 %  Group Project Submissions: -Project outline (3 % ) - 1 page with Title, Introduction, Body, and Conclusion (week 6) - 3MT Style Video (6 %) – 3 min (or less) video presentation (week 11) - Academic Poster (6%) – 750-1000 words (week 12) - Participation ( out of 10 and Multiplied by your group mark) Your Group will be between 5-6 Members  You are advised to meet with your group weekly  Form an online network for easy communication e.g. WhatsApp group  Assign roles to each member  Assign deadlines  Group Project Topics 1. Diabetes Mellitus: How does Double Diabetes develop? 2. Prader Willi Syndrome: Genetic imprinting and chromosome 15q deletion. 3. Breast Cancer: BRAC Gene Mutation 4. HIV Infection: Mechanism of viral entry, reverse transcription, and replication. 5. Cushing Disease: Cortisol, adrenal tumours, and hormone regulation. 6. Graves' Disease: Autoimmune thyroid dysfunction and hormone production. You are to explore 7. Klinefelter's Syndrome: XXY karyotype, hormones, and development. 8. Galactosemia: Galactose metabolism, enzyme defects, and toxicity. 9. Wilson’s Disease: Copper metabolism and ATP7B gene mutations. and report on the BIOCHEMIC 10.COVID-19 Cytokine Storm: Cytokines, inflammation, and severe COVID-19 cases. 11.Arsenic Poisoning: Mechanisms of arsenic toxicity and enzyme interference. 12.Paraquat Toxicity in Humans: Oxidative stress and mitochondrial damage. AL Basis of your 13.Parkinson's Disease: Alpha-synuclein, dopamine, and mitochondrial dysfunction. 14.Ivermectin Action: Neurotransmission in parasites and anti-parasitic use. 15.Alzheimer's Disease: Amyloid Beta and Tau Protein Pathology 16.Sickle Cell Anemia: Hemoglobin Structure and Function topic. 17.Huntington's Disease: CAG Repeat Expansion and Protein Aggregation 18.Multiple Sclerosis: Autoimmune Attack on Myelin (check my 19.Cystic Fibrosis: CFTR Gene Mutations and Ion Transport 20.Hemochromatosis: Iron Overload and HFE Gene Mutations eLearning for 21.G6PD Deficiency: Glucose-6-Phosphate Dehydrogenase Enzyme and Red Blood Cell Breakdown group 22.Phenylalanine Hydroxylase Deficiency: Biochemistry of Phenylalanine Metabolism assignments) 23.Tay-Sachs Disease: Hexosaminidase A Deficiency and Ganglioside Accumulation 24.Amyotrophic Lateral Sclerosis (ALS): Protein Misfolding and Aggregation (e.g., TDP-43) 25.Hemophilia: Blood clotting and deficiency of clotting Factors and genetic basis This Lecture 1.Cell Function 2. DNA and RNA structure and function The Cell Functional Features: 1.Cell Development 2.DNA & RNA replication, repair and translation 3.Transport Mechanisms 4.Delivery and removal of substances 5. Respiration Cell Development - Mitosis and Cell growth (somatic Cell?) - Meiosis - (Gametic Cell?) 4 What is a Mitosis ? The Cell Cycle The Cell Cycle 1.Interphase → G1 - Gap 1 Phase – Organelles replicate S - Synthesis Phase – DNA Replication G2 - Gap 2 Phase – Enzyme and Chemicals needed for cell division produced NB: Most of a cells life is spent in Interphase. 2. Prophase → 3. Metaphase → Mitosis 4. Anaphase → 5. Telophase → The Cell Cycle – Mitosis Prophase : Chromosomes Condense & Attach Chromatin condense and become visible, with two chromatids, joined by the centromere. Spindle Fibers form from Centrioles Centrioles migrates to opposite poles of the nucleus Nuclear membrane breaks down Spindle fibers attach to centromeres The Cell Cycle – Mitosis Metaphase : Chromosomes Align Spindle fibers move chromosomes to align at the equator of the cell The chromosomes now aligned is called the Metaphase plate The Cell Cycle – Mitosis Anaphase : Chromosomes Separate Centromere degradates, freeing chromatids Freed chromatids pulled by spindle fibers to opposite poles. The Cell Cycle – Mitosis Telophase : Chromosomes Relax Chromosomes cluster at opposite poles and begin de-condensing Constriction begins to form to divide cell Nuclear envelopes reform Centrioles disassemble and spindles Broken down. The Cell Cycle – Mitosis Cytokenisis : Cells Separate In animal cells, cleavage constriction extended to split cells into two daughter cells. All of the cytoplasm content is Distributed among both daughter cells. The Cell Cycle – Mitosis Regulation – Check points to make sure cell cycle occurs accurately – if not it stops cell from dividing 1- G1/S- Primary Check point- Influenced by cell conditions 2- G2/M- All 3 Interphase steps complete, mitosis can begin 3. Spindle Check point- All chromosomes attached to spindle fibers 5 What is a Meiosis ? Meiosis Two rounds of cell division to create 4 haploid cells. Gamete – A mature male (sperm) or female (egg) sex cell, haploid. Zygote – Two gametes join to form a diploid cell, matures into infant. Haploid- Contains half the number of chromosomes e.g. Humans – n=23 Diploid- Contains all pairs of chromosomes. e.g. Humans – 2n=46 Meiosis Differences between … Mitosis Meiosis One round of Two Rounds of division division 2 daughter 4 daughter cells cells Diploid (2n) Haploid (n) Somatic cells Gametic cells No pairing Homologous pairing No crossing Crossing over over Meiosis Sources of genetic variability …. Prophase 1- Homologous pairing and crossing over , DNA exchange Metaphase 1- Random alignment of homologous pairs Telophase 2- Sort randomly into 4 daughter cells Humans with n=23 → Over a million possible gametes DNA Replication, Repair and Protein Synthesis 6 How is DNA copied ? DNA Replication Key points … Replication occurs so that daughter cells will have the same genetic instructions as the parent cell (mitosis) Each strand (parent strands ) is used as a template to create two new double stranded DNA ( Semi-conservative replication) DNA replication occurs in 5’ to 3’ direction DNA rep. begins at origin of replication Primers need to be added to template strand first to initiate replication (leading -1 primer, lagging strand – 1 per fragment) Replication of both strands at the same time , One continuous synthesis (leading strand) and discontinuous synthesis (lagging strand) DNA Replication Enzymes and proteins in Replication… 1. Helicase – Separates double helix strands 2. Single stranded binding Proteins (ssBP)- Stabilize new single strands 3. DNA Gyrase- Prevents super-coiling 4. DNA polymerase – Attaches new nucleotides to form daughter strand 5. Beta Clamps – Hold DNA polymerase in place 6. Primase – Attach Primers 7. DNA Ligase – Ensure fragments are bonded AATTGCCGCA TTAACGGCGT DNA Replication Telomare A telomere is a region of repetitive nucleotide sequences at each end of a chromatid Protects the end of the chromosome from deterioration o r Acts as the tip of a shoelace In every round of replication, they become shorter and shorter. Shortened telomares can result in unstable DNA causing signs of  7 Protein Synthesis → Translation and Transcription Protein Synthesis Key points … Transcription – is the first step of gene expression, in which a particular segment of DNA is copied into RNA (mRNA). Translation - messenger RNA (mRNA is decoded by a ribosome to produce a specific amino acid chains, or polypeptide which folds into an active protein. Gene – Area of DNA which codes for a certain protein Locus – Specific location or position of a gene in the DNA Promoter Sequence – The start of a gene where transcription begins Termination Sequence – The end of a gene where transcription finishes Codon- Sequence of 3 bases in mRNA that corresponds to one of 20 amino acids (AA) Protein Synthesis Transcription 1. Initiation -Gene switched on – RNA polymerase attach at promoter region ( TATA box?). occurs on one strand 2. Elongation- Free bases are added, to form messanger RNA (mRNA), complimentary to the DNA bases. 3. Termination- When the termination/stop sequence is reached for Protein Synthesis Transcription NB: The mRNA strand is now transported out of the nucleus through the nuclear pore , into the cytoplasm for translation. Post-transcriptional Modification – before the mRNA is translated, parts of it need to be cut shifted around or modified. E.g. to remove promoter sequence. Protein Synthesis Translation 1. Initiation – ribosomes bind to mRNA, ribosome read the code in mRNA to produce a chain of AA. 2. Elongation – tRNA carries the AA to the ribosomes. mRNA is read three bases at a time (codons) which correspond to the anti-codons on the tRNA, which is delivered with the AA attached. e.g. ACC ↔UGG -The AA chain grows longer as peptide bonds form. 3. Termination- when last AA is added , the chain folds to form the Protein Synthesis Translation Post – Translational Modification – Proteins fold and may have carbohydrate, or lipid moiety added to it (Where ?) Protein Folding 1 ˚ -Primary2 ˚ -Secondary 3 ˚- Tertiary 4 ˚ -Quaternary Next Lecture 1. Cell Physiology – Membrane Structure 2. Active vs. Passive Transport 3. Body Fluid components Friday 20th September 2019 8am-12pm, El Dorado