Evolution - Cell structure and function Part 2 17 July 2012

Organelles in a cell:

Cell Wall

·        Most commonly found in plant cells and bacteria (not in animal cells)

·        Surrounds the cell membrane

·        Rigid structure that maintains the shape, support and protects cells

·        Permeable to small molecules and small proteins only

·        It is fully permeable

Cell Membrane

·        Selectively / Partially permeable membrane of cell that controls movement of substances in and out of the cell (NOTE: cannot use semi permeable!)

Structure of the cell membrane

 (image taken from: http://library.thinkquest.org/C004535/eukaryotic_cells.html) 

Nucleus

·        Contain chromatins that control cell activities

·        Chromatin contain DNA which is the genetic material

·        DNA contain instructions for traits and characteristics and to carry out the cell’s function

·        Separated from cytoplasm by nuclear membrane

Cytoplasm

·        Gel-like mixture

·        Surrounded by cell membrane

·        Contains organelles

Mitochondria

·        Referred to as the “powerhouse” of the cell

·        The food we eat is transformed into energy (ATP) for the cell and our bodies. 

 

 

                     Mitochondria

(image taken from: http://www.biotechlearn.org.nz/themes/barcoding_life/images/diagram_of_a_mitochondrion)

 

 

Endoplasmic Reticulum

·        An interconnected network of tubes and vesicles

·        Synthesis of proteins, fats, steroid

·        Transports materials around in cell

·        Smooth type: lacks ribosomes

·        Rough type: ribosomes embedded in surface

(image taken from: http://ed101.bu.edu/StudentDoc/Archives/fall03/dricard/structurespage.html)

(image taken from: http://legacy.owensboro.kctcs.edu/gcaplan/anat/study%20guide/api%20study%20guide%20d%20cell%20structures.htm)

Ribosomes

·        Each cell contains thousands of ribosomes

·        Make proteins

·        Found on endoplasmic reticulum and floating throughout the cell

 

(image taken from: http://liquidbio.pbworks.com/w/page/11135292/Shaan%20Gurnani%20Organelles%20Project)