Cells: Basic Unit of Life Review PDF

Cells: Basic Unit of Life A Review Department of Medical Technology, Biochemistry Cluster – 2022-2023 Introduction to Biochemistry What is Life? Life is a complex and dynamic. All organisms are composed of organic (carbon-based) molecules that...

Cells: Basic Unit of Life A Review Department of Medical Technology, Biochemistry Cluster – 2022-2023 Introduction to Biochemistry What is Life? Life is a complex and dynamic. All organisms are composed of organic (carbon-based) molecules that are responsible in different processes in the body such as growth and development Life is organized and self-sustaining. Living organisms are highly organized systems from biomolecules to the formation of organs in the body system Life is cellular and information-based. Cells differ widely in structure and function but have parts that are involved in different important chemical processes Characteristics of Life Cellular Organization – living organisms are made up of cells that can be unicellular or multi-cellular Homeostasis – it is the ability of an organism to maintain constant internal conditions (example: body temp, pH level, water level) Metabolism - living processes consist of various biochemical reactions that obtain and use energy Reproduction – the ability to form an offspring (may be sexual or asexual) What is Biochemistry? Biochemistry is the branch of science that explores the chemical processes within and related to living organisms. It is a multidisciplinary study that investigates the molecular basis of life Knowledge in biochemistry can be applied in medical science, environmental science, agriculture, nutrition, etc. Features of Living Organisms Cells are the fundamental units of life. They are functional ang highly organized entities Living processes consist of various biochemical reactions. Thus, these need regulation to maintain life Features of Living Organisms All organisms use the same type of biomolecules: Proteins Nucleic acids Carbohydrates Lipids Cell: The Fundamental Unit of Life Types of Cells: 1. Prokaryotic cells Small sizes; simple structures Single-celled (unicellular) organisms Bacteria and archaea 2. Eukaryotic cells More complex; contain a nucleus Can be unicellular or multicellular Plants, Protists, Animals Prokaryotes VS Eukaryotes Prokaryotic Cell: Structure and Function Most prokaryotes have these common features: cell walls, plasma membrane, circular DNA, no internal membrane organelles Cell wall- primary source of support; maintains the organism’s shape and protects it from mechanical injury Plasma membrane- directly inside the cell wall; acts as a selective permeability barrier Cytoplasm- a compartment that holds the nucleoid (contains small circular DNA) Pili and flagella- hair-like structures used for locomotion and attachment of food Eukaryotic Cell: Structure and Function Cell or Plasma membrane composed of a lipid bilayer; provides shape, mechanical strength, protection, and permeability barrier to the cell Compartmentalizes the cell Eukaryotic Cell: Structure and Function Cytoplasm or Cytosol gel-like, water-based fluid that occupies the majority of the volume of the cell surrounds and protects the organelles of the cell site for energy production, storage and manufacture of cellular components Eukaryotic Cell: Structure and Function Nucleus- contains the cell’s hereditary information; control system of the cell in metabolic activities Nucleoplasm- provides rigidity to the nucleus; site of DNA and RNA synthesis Nuclear envelope- separates components of the nucleus from the cytoplasm; contains nuclear pores that controls passage of biomolecules Nucleolus-site or ribosomal RNA synthesis Eukaryotic Cell: Structure and Function Rough Endoplasmic reticulum (RER) involves in the synthesis of membrane proteins and proteins for export from the cell Characterized with flattened sheets with presence of ribosomes on the cytosolic side of the membrane Smooth Endoplasmic reticulum (SER) responsible for lipid synthesis and biotransformation (water-insoluble organic molecules are prepared for excretion) Tubular in shape Eukaryotic Cell: Structure and Function Ribosomes RNA protein complexes responsible for protein synthesis Contains two irregularly shaped subunits Golgi apparatus formed by fusion of vesicles that split off the ER involves in packaging and distribution of proteins and lipids to internal and external compartments; Eukaryotic Cell: Structure and Function Lysosomes-digests excess or worn-out biomolecules by endocytosis Peroxisomes-involves in the ROS detoxification; breaks down toxic molecules such as peroxides Eukaryotic Cell: Structure and Function Mitochondria Synthesized from free ribosomes powerhouse of the cell responsible for ATP synthesis or energy from the breakdown of carbohydrates and lipids Thank you for Listening!