Cell Biology PDF

Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept CELL BIOLOGY Introduction: Biology is a science of life concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, an...

Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept CELL BIOLOGY Introduction: Biology is a science of life concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Moreover, biology is concerned with the study of the interrelationship of organisms and evolution of life, transmission of information and flow of energy through the living system, the medical applications of cell biology became more interesting now a days. They can be seen not only in diagnosis and treatment such as organ transplantation and gene therapy, but also in genetic engineering to increase food production and improve genetic characters of animal and plant. Biological science: The science that studies living organisms. Genetics: The branch of biology that studies hereditary and variation in organisms. Histology: The branch of biology that studies the structure and function of organs tissues. Cell biology also called cellular biology or Cytology (Cyto means cell; -logy means science) is the branch of biology that studies the basic structure, function and chemistry of cells. The cell is the smallest biological unit. It is the structural and functional unit of all living forms; unicellular ( as bacteria) and multicellular organisms( as human). Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept What is a living thing? Properties of living things: Composed from cells (one or more). Surrounded by membrane, allows necessary material in, and restricts damaging and unnecessary substances. Respond to the environment. Composed of biological molecules. Reproduction: produce offspring (mitosis). Have metabolism: convert oxygen and nutrients into ATP (energy). Evolve and adapt to environment. Maintain homeostasis (body's ability to maintain constant internal environment). Life has many levels of Organization: 1. The chemical organization (molecules). 2. The cellular organization. 3. The tissue level of organization. 4. The organ level of organization. Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept 5. The systems level of organization. Characteristics of Living Things: 1. Living things are highly ordered (or organized). Atom: smallest particle into which you may divide an atom and keep properties of that atom. Molecule: two or more molecules bonded together. Organelle: structures, taken together, make up cells. Cell: the simplest entity with all the properties of life. Tissue: groups of cells with the same function. Organ: group of tissues serving same function. Organ System: a group of organs that perform the same function, eg, the digestive system. Organism: species (Example: Humans). Population: a group of individuals of the same species in a given area. Community: all the populations in a given area. Ecosystem: the community plus the nonliving components such as air, water, energy, soil, etc. Biosphere: all life on earth. 2. Metabolism - living things must gather and use energy to maintain order. 3. Motility - self-propelled motion Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept 4. Responsiveness (sensitivity) - response to their environment. (e.g. detect cold, heat, food, water, etc). 5. Reproduction suite of mechanisms by which they give rise to new organisms. 6. Development - changes from conception to sexual maturity (and even to death). 7. Genes - units of inheritance composed of DNA. 8. Living things evolve - change over time. 9. Adaptiveness - over time genetic modifications that allow organisms to cope with their environment Units of measurement used in cell and molecular biology. 1Angstroms 10A 100A 1000A 10.000A 10.000.000A 1nanometer 10nm 100nm 1000nm 1.000.000nm 1micrometer 100µm 1mm Types of cells: 1- Prokaryotes: organisms lack of nucleus and envelope and just nuclear material. 2- Eukaryotes: organism or cells contain nucleus that contain chromatin material inside nuclear envelope. Lecturer Ola H Hazim Human Biology 1st Pharmacy Dept Life Elements: Typical living thing composed (99.9% wt) of six elements: C, H, N, O, P, and S. Other elements occur in traces. Atoms - smallest particle into which an element can be divided and still have the properties of that element. Main particles that go to make up the atom, and which under normal circumstances do not split-of, are: I. Protons. II. Neutrons. III. Electrons. Molecule - is two or more atoms joined together by molecular bonds. (grouping of atoms in compounds).