Cell membrane and its detailed characters by NNM.pptx

-Bacteria
Bacterial cell wall
Types of bacterial cell wall
Comparison between the Gram(+) & Gram(-) Cell wall
why gram negative bacteria are more resistance?
Function of bacterial cell wall
Fungal cell wall
Function of fungal cell wall
Plant Cell Wall
active and passive transport
endocytosis
exocytosis
osmosis

1. Cell membrane/Cell wall and Cell Surface

2. Bacteria ( singular : bacterium ) constitute a large domain of prokaryotic microorganisms . The study of bacteria is known as bacteriology , a branch of microbiology . Bacteria was first discovered by Antony van Leeuwenhoek in 1970s. Bacteria Fig:- structure of bacteria

3. Different shapes of Bacteria

4. Bacterial cell wall is a rigid structure that gives the shape of the cell. Unique to bacteria. Protecting cells from osmotic lysis. Bacterial cell wall Cell Wall Cytoplasm Cell membrane

5. Peptido-glycan Polymer (amino acids + sugars) Sugars; NAG & NAM N-acetylglucosamine (G) N- acetymuramic acid (M) Structure and Chemical composition of Bacterial cell wall

6. According to the position of the peptidoglycan layer in the cell wall bacteria are classified into two types. Gram-positive bacteria Gram-negative bacteria Types of bacterial cell wall

7. In gram positive bacteria The thick  peptidoglycan  layer in the  cell wall  that encases their  cell membrane

8. In Gram negative bacteria the thin  peptidoglycan  layer of their  cell wall  is sandwiched between an inner  cell membrane  and a  bacterial outer membrane .

9. Comparison between the Gram(+) & Gram(-) Cell wall

10. why gram negative bacteria are more resistance? The distinctive feature of gram-negative bacteria is the presence of a double membrane surrounding each bacterial cell. Although all bacteria have an inner cell membrane , gram-negative bacteria have a unique outer membrane. This outer membrane excludes certain drugs and antibiotics from penetrating the cel l, partially accounting for why gram-negative bacteria are generally more resistant to antibiotics than gram-positive bacteria. The outer membrane of gram-negative bacteria is rich in a molecule called lipopolysaccharide. If gram-negative bacteria enter the bloodstream, lipopolysaccharide can trigger a cascade of events, including high fever and a drop in blood pressure. For this reason, lipopolysaccharide is often referred to as an endotoxin.

11. Protect cells against osmotic shock (most important) and physical damage. Regulation of substance transport into and out of cells. Contain genome. Contain supplemental genetic information such as resistance to antibiotics, production of toxins and tolerance to toxic environment. Take part in protein synthesis. Movement of cells. Mineral storage of cells. Function of bacterial cell wall

12. Fungi are eukaryotes Nearly all multicellular (yeasts are unicellular) Spore-bearing protists that lack chlorophyll. Two types:- 1. Yeasts 2. Moulds (filamentous and multicellular) Fungi

13. The cell wall is made up of: C hitin (polymers of acetylated amino sugar N -acetyl-glucosamine) G lucan Proteins Glucan and chitin are components of the primary wall. Proteins are components of the secondary wall. Other components include chitosan, melanin's and lipids. Enzymes include cellulase which acts on the cellulose of plants. Fungal cell wall

14. Basic component of fungal cell wall

15. Protects against osmotic lysis Acts as a molecular sieve Contains pigments for protection Binding site for enzymes The outermost surface of the cell wall provides a medium between the cell and the environment a site where antigen and agglutinin get attached to the substrate, host and other cells. Function of fungal cell wall

16. A cell wall is a structural layer surrounding some types of cells, situated outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell wall is a rigid & rough. Situated outside the cell membrane. The cell wall was discovered by Robert Hooke in 1665. Plant Cell Wall

17. Major Regions of the Cell Wall

18. Components of the cell wall

19. Composition In the primary (growing) plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. secondary cell walls) include: cellulose, 35-50% xylan , 20-35%, a type of hemicellulose lignin, 10-25%, a complex phenolic polymer that penetrates the spaces in the cell wall between cellulose, hemicellulose and pectin components, driving out water and strengthening the wall.

20. determining cell shape support and mechanical strength prevents the cell membrane from bursting controls cell growth and cell volume physical barrier carbohydrate storage Functions of the Cell Wall