河南师范大学：《生物化学》课程PPT教学课件（英文版）Section A Cell organization

A Cell organization Al Prokaryotes A2 Eukaryotes A3 Microscopy A4 Cellular fractionation

A Cell organization A1 Prokaryotes A2 Eukaryotes A3 Microscopy A4 Cellular fractionation

A1 Prokaryotes Prokaryotes Celll structure Bacterial cell wallls

A1 Prokaryotes ➢ Prokaryotes ➢ Cell structure ➢ Bacterial cell walls

Prokaryotes Prokaryotes are the most abundant organisms on earth(bacteria and blue-green algae A prokaryotic cell dose not contain a membrane bound nucleus Size from 0.1 to 10 um

Prokaryotes Prokaryotes are the most abundant organisms on earth. (bacteria and blue-green algae) A prokaryotic cell dose not contain a membrane￾bound nucleus. Size from 0.1 to 10 μm

Three basic shapes 1. I Spherical(coc:球菌) 2. Rodlike( bacilli:细菌,杆菌) 3. Helically coiled( spirilla:螺旋菌) > They fall into two groups: the eubacteria真细菌 and the archaebacteria(古细菌)

Three basic shapes 1. Spherical(cocci:球菌) 2. Rodlike(bacilli:细菌，杆菌) 3. Helically coiled( spirilla:螺旋菌) ➢ They fall into two groups:the eubacteria 真细菌and the archaebacteria（古细菌）

he eubacteria(真细菌) 1.Gram-positive 2. Gram-negative 3. Cyanobacteria( cyano深蓝色的 bacteria) in soil, water and living in or on larger organisms

The eubacteria(真细菌) 1. Gram-positive 2. Gram-negative 3. Cyanobacteria (cyano深蓝色的-bacteria) in soil,water and living in or on larger organisms

The archaebacteria ☆ Sulfur硫 bacteria 令 Methanogens( methane甲烷) They grow in unusual environments: salt brines, hot acid springs, in the ocean depths

The archaebacteria ❖ Sulfur硫 bacteria ❖ Methanogens（methane-甲烷） They grow in unusual environments: salt brines,hot acid springs,in the ocean depths

Cell structure Each'prokaryotic cell is surrounded by a plasma membrane 质膜 The cell has no subcellularorganelles, only infoldings of the plasma membrane called mesosomes中间体 The deoxyribonucleic aid (DNA)is condensed within the cytosol to form the nucleoid拟核 Some prokaryotes have tall-like flagella鞭毛

Cell structure • Each prokaryotic cell is surrounded by a plasma membrane 质膜. • The cell has no subcellular organelles,only infoldings of the plasma membrane called mesosomes中间体. • The deoxyribonucleic aid (DNA) is condensed within the cytosol to form the nucleoid拟核. • Some prokaryotes have tall-like flagella鞭毛

Cell structure Prokaryotic cell Structure eyt。 past Nucleoid capsul Cell wall yt。 plasmic Membrane es Flagella igure

Cell structure

Bacterial cell walls The peptidoglycan (protein and oligosacca-ride)cell wall protects the prokaryotic cell from mechanical and osmotic pressure. A Gram-positive bacterium has a thick cell wall surrounding the plasma membrane, whereas Gram negative bacteria have a thinner cell wall and outer membrane, between which is the periplasmic space

Bacterial cell walls • The peptidoglycan (protein and oligosacca-ride) cell wall protects the prokaryotic cell from mechanical and osmotic pressure. • A Gram-positive bacterium has a thick cell wall surrounding the plasma membrane,whereas Gram￾negative bacteria have a thinner cell wall and outer membrane,between which is the periplasmic space

Gram negative cell walls protein LPS ponn polysaccharide lipid A outer membrane peptidogly cytoplasmic membrane phospholipid

Gram negative cell walls