W1 Cell Biochemistry PDF - OLU-Laguna 2024-2025

BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/L...

BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 TOPIC OUTLINE TYPES OF CELLS I Cell Overview A Molecular Composition of Cell II Type of Cell A Prokaryotic Cell B Eukaryotic Cell i Structure and Function III Important Notes in Eukaryotic Cell IV Important Notes in Prokaryotic Cell V Cell Membrane Transport A Passive Transport B Active Transport PROKARYOTIC CELL VI Cell Life Cycle VII Cell Death Structure Feature Molecular Composition CELL Cell wall, Pili, Polysaccharide chains cross-linked by Flagella proteins; coated with lipopolysaccharide; pili and flagella are extensions of the cell wall Mesosome Bilayer of 40% lipid, 60% protein, carbohydrates Nucleoid Region Contains chromatin, a complex of chromosomal DNA and histone proteins Ribosomes Complexes of RNA (65%) and proteins (35%) Vacuoles Nutrients stored in small molecules or polymers  Overview of the Cellular Basis of Life Cytoplasm Small molecules, soluble proteins, ➔ Universal functional unit of all forms of life. enzymes, nutrients, inorganic salts; ➔ Composed of 4 significant elements dissolved in aqueous solution ➔ Homoeostasis (responsible for balance)  Historical Notes on Cell ➔ Robert Hooke - Cell EUKARYOTIC CELL ➔ Matthias Schleiden and Theodor Schwann – All plant and animal tissues were composed of cells. Structure Feature Molecular Composition ➔ Rudolf Virchow – Theory of Biogenesis (cell -> preexisting cell) Cell membrane Bilayer of proteins (50%) and lipids (50%) and some carbohydrates CELL THEORY Nucleus Contains genomic DNA and histone proteins which form chromatin; RNA  The activity of an organism depends on the collective activities of its cells. Endoplasmic Flat, single membrane vesicles of  Principle of complementarity Reticulum with lipids and proteins; ribosomes consist ribosomes of RNA and proteins MOLECULAR COMPOSITION OF CELL Mitochondria Double-membrane with proteins and  Water – 70 – 75% lipids; interior (matrix) contains soluble  Organic Compounds – 25 – 30% and insoluble enzymes, RNA and DNA  Proteins – 10 – 20%  Nucleic Acids – 7 – 10% Lysosomes Single-membrane vesicles containing  Polysaccharides – 2 – 5% (animals) enzymes for hydrolysis  Lipids – 3%  Inorganic Compounds (Na, K, Mg, Cu)  Protein is the most abundant Inorganic Compounds TRANSCRIBED BY | ELNAR, MKC 1 of 6  BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 PHOSPHOLIPID MOLECULES Peroxisomes Single-membrane vesicles containing (animals) catalase and other oxidative enzymes  phosphatidylcholine (PC)  phosphatidylethanolamine (PE) Cytoplasm Cytoskeleton made of proteins; small  phosphatidylserine (PS) molecules, soluble proteins, enzymes,  phosphatidylinositol (PI) nutrients, and salts in aqueous solution  sphingomyelin  Function ➔ Fluid and dynamic EUKARYOTIC CELL STRUCTURE AND FUNCTION ➔ Semi permeable  Cells - Tissues or organs - Whole organisms ➔ Acts as a physical barrier  These cells differ in size and shape, but they are ➔ Cell Communication certain common structural features. NUCLEUS  Structure ➔ Centre of the cell ➔ Nuclear Envelope SUBCELLULAR STRUCTURES OF EUKARYOTIC CELL AND THEIR FUNCTION  Semi permeable double layer membrane ➔ Nuclear pores  Cell communication PLASMA MEMBRANE/CELL MEMBRANE ➔ Nucleolus  Structure ➔ Nucleoplasm/Nuclear matrix ➔ Outermost structure of the cell ➔ Phospholipid bilayer  Involved in the synthesis of DNA and RNA ➔ Fluid mosaic model  Function  Function ➔ Information Centre ➔ Fluid and dynamic ➔ It contains the DNA that serves as the genetic ➔ Semi permeable material for ➔ Acts as a physical barrier ➔ directing protein synthesis. ➔ Cell Communication TRANSCRIBED BY | ELNAR, MKC 2 of 6  BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 LYSOSOMES  Structure ➔ “Suicide/al bags” of the cell ➔ Spherical shaped membrane bound organelles formed from the Golgi apparatus. ➔ Contains digestive enzymes (lysosomal enzyme)  The fluid inside lysosomes is much more acidic, at about pH 4.8, than the normal Ph of about 7.0–7.3.  Function CYTOPLASM ➔ Digest microbes or materials by the cell  Structure ➔ Extra nuclear cell content that possesses both organelles and other material  CYTOSOL - Fluid part of the cytoplasm - viscous fluid medium  Function ➔ It is responsible for various cellular processes. MITOCHONDRIA  Structure ➔ Ellipsoidal in shape ➔ Outer membrane = equal amount of protein and lipids. CYTOMEMBRANES  Highly permeable to small molecules  Extensive network of membranes in the cytoplasm  Porin ➔ Endoplasmic reticulum and Golgi complex or ➔ Inner membrane = 75% protein and the apparatus. remainder are lipids.  Cardiolipin  Cristae ENDOPLASMIC RETICULUM (ROUGH) - knob like structures (head piece, stalk,  Structure and base piece) ➔ Continuous with outer nuclear membrane ➔ Ribosomes  Function ➔ Cisternae ➔ Powerhouse of the cell ➔ It is responsible for the production of energy in  Function the form of ATP. ➔ Modifies, transports, and stores proteins ➔ Energy producing pathways. produces by attached ribosomes. TRANSCRIBED BY | ELNAR, MKC 3 of 6  BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 GOLGI APPARATUS PEROXISOMES  Structure  Structure ➔ Series of several elongated, flattened saclike ➔ Small vesicles surrounded by a membrane. membranous structures.  Function  Function ➔ Detoxify specific harmful substances either ➔ Modifies, packages, and sorts materials, that produced by the cell or taken into the cell. arrive from the endoplasmic reticulum in transport ➔ Involved in the biosynthesis of cholesterol. vesicles IMPORTANT NOTES IN EUKARYOTIC CELL  Ion channels ➔ They are involved in transport of ions between cytosol.  Vacuoles  Cell Coat IMPORTANT NOTES IN PROKARYOTIC CELL  Prokaryotes (Eubacteria and Archaebacteria) are the most abundant organisms on earth.  Does not contain a membrane-bound nucleus.  Surrounded by a plasma membrane.  No subcellular organelles  Mesosomes CYTOSKELETON  DNA is condensed within the cytosol to form the  Structure nucleoid.  Some prokaryotes have tail-like flagella. ➔ Organized network of protein filaments  Function ➔ Maintains integral structural support and organization of cells.  Microfilaments  Intermediate filaments  Microtubules CELL MEMBRANE TRANSPORT TRANSCRIBED BY | ELNAR, MKC 4 of 6  BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 PASSIVE TRANSPORT PROCESS DIFFUSION  Area of its higher concentration to an area of its lower concentration ➔ Simple diffusion ➔ Facilitated Diffusion ➔ Osmosis CELL LIFE CYCLE SODIUM-POTASSIUM PUMP  All forms of life growth require cell division.  sodium–potassium activated ATPase.  Biochemical and morphologic four-stage process through which a cell passes when it is stimulated to ➔ Na out - K in divide. ➔ G1 (gap 1)  Period of cell growth and synthesis of components necessary for replication. ➔ S (DNA synthesis)  DNA replication  Duplication of Centrosome ➔ G2 (gap 2)  Check for proper replication and damage. ➔ Mitosis MITOSIS EXOCYTOSIS  Division of chromosomes and cytoplasm into two  Process by which cells release substances outside daughter cells the cell.  Fusion of secretory vesicles to PM ➔ Prophase  Each chromosome consists of two chromatids joined at the centromere. ENDOCYTOSIS ➔ Prometaphase  Process by which cells take in substances from  The nuclear envelope disassembles, outside the cell. centrosomes move to opposite cell poles, forming the origin of mitotic spindle fibers, TRANSCRIBED BY | ELNAR, MKC 5 of 6  BIOCHEM W1: CELL ST Trixie Anne R. Molina RMT PRELIMS 1 Semester LEC/LAB OLFU - LAGUNA SY 2024-2025 while sister chromatids attach to these fibers. ➔ Metaphase  Chromosomes align at the center of the cell. ➔ Anaphase  Chromatids separate at the centromere and migrate to opposite poles. ➔ Telophase  Two new nuclei assume their normal structure, and cell division is completed, producing two new daughter cells. ➔ Cytokinesis CELL DEATH  Cells are not immortal.  Tissue homeostasis  Development or during recovery from injuries  Necrosis ➔ Damaged ➔ Decrease oxygen supply. ➔ ATP production is blocked.  Apoptosis ➔ Tissue turnover ➔ Aged cells  Apoptosis ➔ Absence of essential survival factors  e.g Absence of nerve growth factor leads to atrophy of nerves. TRANSCRIBED BY | ELNAR, MKC 6 of 6