Cтруктурно-функциональная организация генов и белков

Измерения:
1 сантиметр (cм) = 10-2 метра (м)
1 миллиметр (мм) = 10-3 м
1 микрометр (μм) = 10-3 мм = 10-6 м
1 нанометр (нм) = 10-3 μм = 10-9 м

Уровни организации (международная классификация, 2011 год):
Atoms
Molecules
Assemblies
Cells
Tissue Organ
Organ system
Organism
Population

Растительные клетки (большая часть биомассы на планете) пища, топливо, материалы, витамины и т.д.

Химический состав типичной клетки
Макромолекулы
(биополимеры)

Общий принцип образования и распада биополимеров
синтез………
распад.............

Всего 20 аминокислот участвует в образовании белков и других реакциях
(международные названия и классификация):

Аденозинтрифосфат - АТФ
АТФ – нуклеотид
предшественник биосинтеза нуклеиновых кислот
источник энергии
медиатор, нейротрансмиттер, регулятор

Строение нуклеиновых кислот:

Строение липидов:

Строение липидов:

Разнообразие комбинаций трех полимеров определяет разнообразие живого на планете. Растения, животные и грибы имеют одинаковые «мономеры» и принципы их соединения в макромолекулы, но благодаря отличиям в молекулярной структуре и организации, они могут сильно отличаться на клеточной и организменном уровне.

Семь функциональных групп, которые наиболее важны в биохимических процессах:
Гидроксильная
Карбонильная
Карбоксильная
Амино
Сульфгидрильная
Фосфатная
Метильная

Fig. 4-10c
STRUCTURE
EXAMPLE
NAME OF
COMPOUND
FUNCTIONAL
PROPERTIES
Carboxyl
Acetic acid, which gives vinegar its sour taste
Carboxylic acids, or organic acids
Has acidic properties
because the covalent bond between oxygen and hydrogen is so polar; for example,
Found in cells in the ionized form with a charge of 1– and called a carboxylate ion (here, specifically, the acetate ion).
Acetic acid
Acetate ion

Fig. 4-10d
STRUCTURE
EXAMPLE
NAME OF
COMPOUND
FUNCTIONAL
PROPERTIES
Amino
Because it also has a carboxyl group, glycine is both an amine and
a carboxylic acid; compounds with both groups are called amino acids.
Amines
Acts as a base; can pick up an H+ from the surrounding solution (water, in living organisms).
Ionized, with a charge of 1+, under cellular conditions.
(ionized)
(nonionized)
Glycine

Fig. 4-10e
STRUCTURE
EXAMPLE
NAME OF
COMPOUND
FUNCTIONAL
PROPERTIES
Sulfhydryl
(may be written HS—)
Cysteine
Cysteine is an important sulfur-containing amino acid.
Thiols
Two sulfhydryl groups can react, forming a covalent bond. This “cross-linking” helps stabilize protein structure.
Cross-linking of
cysteines in hair
proteins maintains the curliness or straightness of hair. Straight hair can be “permanently” curled by shaping it around curlers, then breaking
and re-forming the
cross-linking bonds.

Fig. 4-10f
STRUCTURE
EXAMPLE
NAME OF
COMPOUND
FUNCTIONAL
PROPERTIES
Phosphate
In addition to taking part in many important chemical reactions in cells, glycerol phosphate provides the backbone for phospholipids, the most prevalent molecules in cell membranes.
Glycerol phosphate
Organic phosphates
Contributes negative charge to the molecule of which it is a part (2– when at the end of a molecule; 1– when located internally in a chain of phosphates).
Has the potential to react with water, releasing energy.

Fig. 4-10g
STRUCTURE
EXAMPLE
NAME OF
COMPOUND
FUNCTIONAL
PROPERTIES
Methyl
5-Methyl cytidine is a component of DNA that has been modified by addition of the methyl group.
5-Methyl cytidine
Methylated compounds
Addition of a methyl group to DNA, or to molecules bound to DNA, affects expression of genes.
Arrangement of methyl groups in male and female sex hormones affects
their shape and function.

James Watson and Francis Crick, UK
Erwin Chargaff, Ukraine
Linus Pauling, USA
Maurice Wilkins, NZ
Rosalind Franklin, UK
Ученые, которые участвовали в открытии структуры ДНК

Первое правило Чаргафа:
В природной ДНК количество единиц гуанина равно количеству единиц цитозина, тогда как количество единиц аденина равно количеству единиц тимина.
В типичной ДНК эукариот
(пример: ДНК человека):
A=30.9%, T=29.4%;
Г=19.9% Ц=19.8%.

Pyrimidines:
uracil, cytosine, thiamine
Purines :
Adenine, guanosine

Структура оснований в ДНК и РНК:
пиримидины:
урацил, цитозин, тиамин
пурины:
аденин, гуанозин

Nucleoside
нуклеозид
Nucleotide
нуклеотид

Разница в сахаре в нуклеиновых кислотах:

Другие функции
нуклеотидов
(помимо генетической):

Study this carefully to memorize general structure and nomenclature.

Размеры спирали:
Водородные связи:
Пространстенное расположение частей (по цветам):

Hydrogen bonding between bases important in double helix. Two between A and T; three between G and C.

DNA to RNA to protein:
a diagrammatic overview of information flow in a cell.
Both DNA and RNA are nucleic acids

Campbell and Reece 8 Figure 17.20 Polyribosomes
mRNA is translated into a polypeptide/protein in the cytoplasm.
Ribosomes are composed of RNA and protein

Campbell and Reece Figure 17.14 The structure of transfer RNA (tRNA).
Transfer RNA is an adaptor molecule bringing in amino acids in the synthesis of protein.

Campbell and Reece 8 Chapter 17
These first three are the types of RNA that you need to know about:
mRNA
tRNA
rRNA

Making a polypeptide chain
Amino acids are linked by the formation of a peptide bond
Note the different side chains of the amino acids
Proteins
What is this reaction called?

The primary structure of a protein is the sequence of amino acids
This is the enzyme lysozyme
There is an amino terminal to the protein, which has an amino group.
The end of the protein has a carboxyl group.

Campbell and Reece
Figure 5.19
Conformation of the enzyme lysozyme. Two types of model, the ribbon model and the space filling model
The substrate molecule in bacterial cell walls binds in the groove

Campbell and Reece 8 Figure 5.21 Exploring levels of protein structure.

Campbell and Reece 8 Figure 5.21 The quarternary structure of proteins.

Campbell and Reece 8 Fig 5.23 Denaturation and renaturation of a protein
Heat, low/high pH

Essential Cell Biology 2
Protein structure and protein-protein interactions are important in viral particle structure