cell: structure and function
DESCRIPTION
RONALDO T. BIGSANG, M.Sc. Assistant Professor Science Department Mindanao State University-General Santos City. CELL: Structure and Function. OUTLINE. Cell Theory: Development and Principles Prokaryotic vs Eukaryotic Cell: Similarities and Differences Organelles: Structure and Function - PowerPoint PPT PresentationTRANSCRIPT
CELL:Structure and Function
RONALDO T. BIGSANG, M.Sc.Assistant ProfessorScience DepartmentMindanao State University-General Santos City
OUTLINE
Cell Theory: Development and Principles
Prokaryotic vs Eukaryotic Cell: Similarities and Differences
Organelles: Structure and Function
Animal vs Plant Cell: A Comparison
CELL THEORY: Its developmentYear of
Discovery Scientist Contribution
1590 Hans & Zacharias Janssen
Dutch; developed the first compound microscope by combining 2 lenses in a tube
1665 Robert Hooke English; discovered small, hollow compartments in a cork of an oak tree --- cells
1675 Anton van Leeuwenhoek
Dutch; observed tiny living organisms from rainwater, saliva, blood --- animalcules
CELL THEORY: Its developmentYear of
DiscoveryScientist Contribution
1838 Matthias Schleiden German; suggested that plants were made up of cells
1839 Theodor Schwann German; suggested that animals are made up of cells
1840 Jan Evangelista Purkinje
Czech; named the cellular content ‘protoplasm’
1855 Rudolf Virchow German; suggested that all cells come from cells
CELL THEORY: Its principles
1) all living things are made up of cells
2) cells are the basic units of life
3) cells only come from pre-existing cells
CELL is described…
as the basic structural and functional unit of life simplest entity capable of carrying out life’s
processes can exist alone (unicellular) or as a complex
organism (multicellular)
to be composed primarily of C, H, O, N minor elements --- Ca, P, K, S, Na, Cl, Mg, I, Fe trace elements --- Cr, Co, Cu, F, Mn, Mo, Se, Si,
Sn, Va, Zn
CELL is described…
to contain over 60 percent water --- homeostasis (buffering effect)
to have carbohydrates, lipids, proteins and nucleic acids as the major biomolecules
to vary in size --- ranges from 0.2μm to 2mm
to vary in shape --- fixed or variable
Table 1. Various cell types and their sizes.
Table 2. Various cell shapes and their examples.
PROKARYOTIC VS EUKARYOTIC
prokaryotic without true nucleus but a
NUCLEOID region genetic material is in DIRECT
contact with the surrounding environment (cytoplasm)
eukaryotic with true NUCLEUS genetic material is ISOLATED
and PROTECTED from the surrounding environment (cytoplasm)
with ORGANELLES
PROKARYOTIC VS EUKARYOTIC
PROKARYOTIC
Plasma Membrane
with NUCLEOID Cytoplasm
NO nucleus DNA (genetic material)
NO organelles Ribosomes
COMMON EUKARYOTIC(to both)
with NUCLEUS
WITH organelles
PROKARYOTIC VS EUKARYOTIC
despite their differences, prokaryotic and eukaryotic cells have COMMONALITIES Plasma Membrane▪ structural barrier separating the cell from the
outside environment; with protective and regulatory functions
PROKARYOTIC VS EUKARYOTIC
Cytoplasm▪ space in the cell where most
cellular activities take place --- “factory area”
▪ contains an intracellular matrix called cytosol where all other cellular components are suspended
▪ organelles --- membrane-bound structures in in eukaryotic cells
▪ inclusions --- non-permanent and inactive substances/materials in the cell (i.e. fat globules, crystals)
PROKARYOTIC VS EUKARYOTIC
DNA (genetic material)▪ “blueprint” of an organism▪ carries all the information
necessary for the growth, development and survival of an organism
Ribosomes▪ small non-
membrane bound structures that act as sites for protein synthesis in the cell
ORGANELLES --- “little organs” membrane-
bound structures performing a specific function in eukaryotic cells
distribution of work in the cell --- maximizes time and space
ORGANELLES --- “little organs”
NUCLEUS
structure double-membraned
structure with nuclear pores that connect the nuclear components to the cytoplasm
control center of the cell
function directs RNA and protein
synthesis stores the genetic
information (DNA)
ORGANELLES --- “little organs”
NUCLEOLUS
structure spherical organelle
within the nucleus
function assembles ribosomes
ORGANELLES --- “little organs”ENDOPLASMIC RETICULUM structure
network of internal membranes (endomembrane system)
divided into 2 regions:▪ rough ER --- with ribosomes▪ smooth ER --- w/out ribosomes
function compartmentalizes the cell
creating a greater surface area for cellular processes to proceed
serves in the transport of cellular products via the formation of vesicles
rough ER fxn: protein synthesis
smooth ER fxn: lipid synthesis, regulates
calcium levels
ORGANELLES --- “little organs”
GOLGI BODIES
structure stacks of flattened
membranous sacs called cisternae
cis face --- accepts incoming transport vesicles from the ER
trans face --- releases secretory vesicles containing the finished product
function modifies and packages
cellular products
ORGANELLES --- “little organs”
MITOCHONDRION
structure hotdog-shaped structure with
smooth outer membrane, folded inner membrane and many respiratory enzymes
intermembrane space separates the outer and inner membranes
folds of the inner membrane are called cristae
matrix is the space within the inner membrane
function produces ATP (aerobic respiration)
ORGANELLES --- “little organs”
LYSOSOME
structure small spherical bodies
containing digestive or acidic hydrolytic enzymes
function digests macromolecules,
cellular debris, old organelles and foreign substances
ORGANELLES --- “little organs”
PEROXISOME
structure small spherical bodies
containing oxidase enzymes
function neutralizes toxic
substances breaks down fatty acids
ORGANELLES --- “little organs”
VESICLES
structure membrane-bound sacs
function store and transport
substances
ORGANELLES --- “little organs”
VACUOLE
structure membrane-bound sacs in animals, many but
small in size in plants, one big
central vacuole
function store water, enzymes,
pigments, waste products
ORGANELLES --- “little organs”
CHLOROPLAST
structure double-membraned, green
oval structure with stacks of sac-like structures within
thylakoid refers to the sac-like structure containing pigments such as chlorophyll and carotenoids
thylakoids stack together to form a granum
function facilitate food production in
photosynthetic organisms
OTHER CELL STRUCTURES
CYTOSKELETON
structure network of protein filaments
including microfilaments, intermediate filaments, microtubules
cilia and flagella --- motility centriole --- anchor and
assemble spindle fibers in animal mitosis
function provides structural support
and movement (in some) to the cell
OTHER CELL STRUCTURES
CELL WALL
structure rigid structure in plants
and members of the kingdom fungi made up of cellulose or chitin, respectively
function provides structural
support to the cell
PLANT VS ANIMAL CELL
END