文档介绍：In the first chapter, we introduced a general outline on what will be of this subject. Now we start to examine details of anisms. Let’s see what anisms look like and what are made of.
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Chapter 2 Structure of Bacteria
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Macromolecules (大分子)
protein, haride, lipids, DNA, RNA, 96% (dw%)
Monomers: (单体及前体)
amino acids and precursors, sugars and precursors 3%
anic ions:
K+, Mg+2, Ca2+, Fe2+, Mn2+, Cu2+、Co2+、Zn+2……1%
position
of a prokaryotic cell
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O
C
C
C
C
Base
H
H or OH
H
H
H
H
CH2
O
P
OH
O
HO
Sugar:
RNA – ribose (OH)
DNA – deoxyribose (H)
Macromolecules
Nucleoside: base + sugar
Bases:
adenine (A), cytosine (C),
guanine (G), thymine (T)
RNA uses uracil (U)
instead of thymine
Remember that carbon in sugar is numbered in sequence!!! How they are numbered?
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C 胞嘧啶
U 尿嘧啶
T 胸腺嘧啶
G 鸟嘌呤
A 腺嘌呤
图1c 核糖
图1b 核苷酸
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A
T
C
G
Question: if a cell DNA contains more G+C than A+T, is it harder or easier to separate plementary chains?
Hydrogen bond
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plementary to each other
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氨基酸一般结构
肽键
Macromolecules
protein
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Size and shape of Bacteria
Average bacteria - um in diam.
Surface area ~12 µm2
Volume is ~4 µm
Surface area to volume is 3:1
Typical eukaryote cell SA/Vol is :1
Food enters through SA, quickly reaches all parts of bacteria
Eukaroytes need structures & organelles
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Approximate size of pared to a typical eukaryotic cell.
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