Anatomy and Physiology: Cell PDF

ANATOMY AND PHYSIOLOGY TOPIC: CELL REFERENCE: ESSENTIAL OF HUMAN ANATOMY (EIGHT EDITION) BY ELAINE MARIEB PROFESSOR: MA. ROSARIO MEÑEZ-QUEJADO, RMT, Ed.D. Cell Functional unit of all living things. Cell Theory: a. All living things are made up of cell. b. Cell is the smallest unit of st...

ANATOMY AND PHYSIOLOGY TOPIC: CELL REFERENCE: ESSENTIAL OF HUMAN ANATOMY (EIGHT EDITION) BY ELAINE MARIEB PROFESSOR: MA. ROSARIO MEÑEZ-QUEJADO, RMT, Ed.D. Cell Functional unit of all living things. Cell Theory: a. All living things are made up of cell. b. Cell is the smallest unit of structure and function of life. c. The cell came from a pre-existing cells. Types of Cell 1. Prokaryotic - no true nucleus - energy is produce in reaction with in the cell membranes. 2. Eukaryotic - with true nucleus - energy produced with in the mitochondria Major Parts of Eukaryotic Cell 1. Cell Membrane 2. Nucleus 3. Cytoplasm Cell Membrane Composed of bilayer phospholipids attached to or embedded in protein. Regulates passages of nutrients, waste products and secretion in and out of cells. With selective permeability. Also called plasma membrane Can easily pass through are the glucose, amino acid, minerals, nutrients, O₂, CO₂ Bilayer Phospolipids Head part- hydrophilic , loves water, pole near water. Tail part- hydrophobic, hates water, pole away from water. Protein Floating in lipid portion Can be: enzyme carrier receptors transport binding site: hormones and chemical messenger GLYCOPROTEIN Determine the blood type, receptors for bacteria, viruses, toxins cell to cell interaction * any changes that occurs may transformed into Cancer Cell. Diffusion Movement of water from higher concentration to lower concentration Diffusion Process: Passive diffusion Facilitated diffusion Active transport Endocytosis/Exocytosis Osmosis Diffusion of water to a semi permeable membrane. Solution A homogenous mixture of two or more substances. Ex. Air we breath (mixture of gases) Sea water( mixture of salts and H₂O) Rubbing alcohol ( mixture of H₂O & alcohol) Composition: Solute- the dissolved substance in a solution. Solvent- dissolving medium in a solution. Type of Solution Isotonic- equal concentration of solute and solvent. (NO CHANGE on CELL) Hypertonic- ↑ solute,↓ solvent (CELL will SHRINK)  Hypotonic- ↓ solute, ↑ solvent ( CELL will SWELL ) Factors Influencing permeability of cell Lipid solubility Size of the pores Electrical charges Nucleus Nuclear membrane - contains holes through which large molecules can enter Nucleoplasm - with gelatinous matrix this is like the cytoplasm. a. Nucleolus-sites where ribosomes are assembled. Ribosomes migrates in cytoplasm and serve as protein synthesis. b. Chromatin/ Chromosomes if cell is not dividing : DNA + protein forms CHROMATIN (scattered in the nucleus) if cell is dividing : Chromatin threads coils & condense to form CHROMOSOMES Cytoplasm Semi fluid, gelatinous nutrient matrix. Site of most cells metabolic reactions Composition: a. Cytosol – semitransparent fluid with H₂O, nutrients, dissolve substances (solutes) b. Inclusion- this is not a functioning units , stores nutrients or cell products like: fat droplet, glycogen granules, pigments (ex. Melanin), mucus, crystals c. Organelles- metabolic machinery of cells. 1. Ribosomes- free in cytoplasm or in membranes. 2. Endoplasmic Reticulum- mini circulatory system. 2.1 Rough Endoplasmic Reticulum- abundant in cells that export protein product. ex. Pancreas cells- deliver digestive enzymes to be deliver to the small intestine. 2.2 Smooth Endoplasmic Reticulum - cholesterol synthesis and breakdown fat metabolism and detoxification of drug. - abundant in LIVER - steroid based hormones- cell testes that manufacture testosterone. 2.3 Golgi Apparatus - traffic director for cellular protein. - the protein accumulate in golgi apparatus with swollen ends travel to the plasma membrane-> pinch off and form secretory vesicle which travel to the plasma membrane. (Exocytosis) 2.4 Lysosomes - demolition site - WBC - membrane of lysosomes are stable but become fragile if without O₂ and ↑ Vit. A and results in self digestion of the cell. 2.5 Peroxisomes -seen in kidney cells and liver - membranous sacs with powerful oxidase enzymes that use O₂ to detoxify poisonous substances including alcohol an formaldehyde. - disarm dangerous free radicals (by products of cell metabolism harmful if accumulated, unpaired electrons that scramble the structure of proteins & nucleic acids). *Peroxisome convert free radicals to hydrogen peroxide (H₂O₂) and in the presence of enzyme catalase convert excess H₂O₂ to water. 2.6 Mitochondria - double wall equal to 2 plasma membrane outer membrane- smooth inner membrane- shelf like protrusion called CRISTAE. - Enzymes in the fluid of mitochondria plus enzymes of cristae membrane will carry reaction in which O₂ is used to breakdown food. Food breakdown -> energy release-> some energy will become HEAT other will be captured and used to form ATP molecules that is used for all cellular works. Ex. Liver & Muscles with huge ATP. cell like unfertilized eggs- mitochondria is few. 2.7. Cytoskeleton  - bones and muscle cell - function: cell shape, support organelles, provide machinery needed for intracellular transport and cellular movement. - made up of : a. Microtubules- cell division, overall shape and distribution of organelle. b. Intermediate Filaments-desmosomes c. Microfilaments- (Actin & Myosin)- cell motility and change in cell shape. 2.8. Centrioles - directs the formation of mitotic spindle. - with fine microtubules internally. a. Cilia- formed by multiplying centrioles and line beneath the plasma membrane and free at the cell surface. Ex. Lung cell. b. Microtubules- sprout from centrioles and pressure on membrane forming projections. c. Flagella- longer projections. ex. Sperm cells. Cell life cycle Cells have two major periods Interphase Cell grow, Cell carries on metabolic processes Cell division Cell replicates itself Function is to produce more cells for growth and repair processes Genetic material duplicated and readies a cell for division into two cells Occurs toward the end of interphase DNA uncoils and each side serves as a template Events of Cell Division Mitosis Division of the nucleus Results in the formation of two daughter nuclei Cytokinesis Division of the cytoplasm Begins when mitosis is near completion Results in the formation of two daughter cells Stages of Cell Division Interphase No cell division occurs The cell carries out normal metabolic activity and growth Prophase First part of cell division Centromeres migrate to the poles Metaphase Spindle from centromeres are attached to chromosomes that are aligned in the center of the cell Anaphase Daughter chromosomes are pulled toward the pole The cell begins to elongate Telophase Daughter nuclei begin forming A cleavage furrow (for cell division) begins to form Protein Synthesis Gene – DNA segment that carries a blueprint for building one protein Proteins have many functions Building materials for cells Act as enzymes (biological catalysts) RNA is essential for protein synthesis Types of RNA Transfer RNA (tRNA) Transfers appropriate amino acids to the ribosome for building the protein Ribosomal RNA (rRNA)  Helps form the ribosomes where proteins are built Messenger RNA Carries the instructions for building a protein from the nucleus to the ribosome Transcription Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA Translation Base sequence of nucleic acid is translated to an amino acid sequence Amino acids are the building blocks of protein.