520 likes | 672 Views
The Cell. Discovery:. The Cell. Anton van Leeuwenhoek. Animalcules. “Corks” - Cells. Robert Hooke. Nucleus. Robert Brown. Mathias Schleiden. Role of nucleus in cell reproduction. Cell Variations. Theodor Schwann. Cells were produced from pre-existing cells. Rudolf Virchow.
E N D
Discovery: The Cell
Anton van Leeuwenhoek Animalcules “Corks” - Cells Robert Hooke Nucleus Robert Brown Mathias Schleiden Role of nucleus in cell reproduction Cell Variations Theodor Schwann Cells were produced from pre-existing cells Rudolf Virchow
Cell Theory • All living things are composed cells • Cells are the smallest working units of all living things • All cells come from pre – existing cells (Virchow)
Types The Cell:
Prokaryotic Cell No defined nucleus No nuclear membrane No membrane-bounded organelles
Eukaryotic Cell Has defined nucleus Has nuclear membrane Has membrane-bounded organelles
Prokaryotes vs. Eukaryotes absent present present Not defined absent present present present absent present
Variations The Cell:
Cell Differentiation • The process of change in shape, size and internal structures
NERVE CELL (Neuron) - is needed for the transmission of messages for the brain to to function *dendrites – receive impulses *axon – transmit impulses
EGG and SPERM CELLS – involved in the transmission of traits to offspring. It carries genetic informations.
RED BLOOD CELLS (RBC) - for transport of oxygen from the lungs to the different organs of the body - contains hemoglobin *heme (iron) *globin (protein)
WHITE BLOOD CELLS (WBC) – to protect the body against invading pathogens *lymphocytes
MUSCLE CELLS - for muscle contraction or movement of the muscles - contains actin & myosin
Organization The Cell:
Levels of Organization Cells Tissues Organs Organ Systems Organism
Structure The Cell:
Cells may differ in: • sizes • shapes • according to the functions which they perform
Cells are similar in: • structure and composition of the protoplasm: 1. Cell membrane 2. Cytoplasm 3. Nucleus (Nucleoplasm)
Cell Cell Membrane Nucleus Cytoplasm
1. Cell Membrane • protection surrounding the cytoplasm
2. Cytoplasm • the region where the main metabolic life activities take place
3. Nucleus • region where the genetic material is located
Parts and their functions The Cell:
Microscope helps us see the minute parts of the cell
other names • composition plasma membrane plasmalemma two layers of phospholipids with scattered proteins and carbohydrates
characteristic very flexible allowing cell to change its shape when needed • functions covers and protects the cell
2. Cytoplasm Site of the metabolic processes of the cell
a. Mitochondria Double membraned “Powerhouse” of the cell
b. Plastids Encloses chlorophyll and site of photosynthesis
c. Ribosomes Manufacturers of proteins
d. Endoplasmic Reticulum Series of canals for protein transport
e. Golgi Apparatus Modifies proteins produced by the ribosomes
f. Vesicles Transports substances in and out of the cell
g. Vacuoles Storage of food
h. Lysosomes Eliminates foreign objects Digests macro molecules
i. Cytoskeleton Micro- filaments
3. Nucleus Brain of the cell
8 9 10 11 12 13
Vesicle 8 Mitochondrion Vacuole Golgi Bodies Lysosomes 9 Nucleolus Rough ER Nucleus Smooth ER 10 Centrioles Microtubules 11 Cytoplasm 12 13 free ribosomes
C A D E J G B H F M I K N L
Cell wall C Lysosomes A Plasma membrane D Ribosomes E J Golgi Body G Plastid Smooth ER B H Plasmalemma F Nucleolus Nucleus M Rough ER I Vacuole K Mitochondrion N Cytoplasm L