What elements predominate in the composition of living organisms. Molecular level: general characteristics - Knowledge Hypermarket

Molecular level: general characteristics

1. What is a chemical element?
2. What is called an atom and a molecule?
3. What organic substances do you know?

Any living system, no matter how complex it may be organized, manifests itself at the level of functioning of biological macromolecules.

Lesson content Lesson outline and supporting framework Lesson presentation Accelerative methods and interactive technologies Closed exercises (for use by teachers only) Assessment Practice tasks and exercises, self-examination workshops, laboratory, cases level of complexity of tasks: normal, high, olympiad homework Illustrations illustrations: video clips, audio, photographs, graphics, tables, comics, multimedia abstracts chips for inquisitive cribs humor, parables, jokes, sayings, crosswords, quotes Add-ons external independent testing (VNT) textbooks main and additional thematic holidays, slogans articles national features glossary other terms Only for teachers

Question 1. What processes are investigated by scientists at the molecular level?
At the molecular level, the most important processes of the life of an organism are studied: its growth and development, metabolism and energy conversion, storage and transmission of hereditary information, variability. An elementary unit at the molecular level is a gene - a fragment of a nucleic acid molecule, in which a qualitatively and quantitatively determined amount of biological information is recorded.

Question 2. What elements prevail in the composition of living organisms?
There are more than 70-80 chemical elements in the composition of a living organism, but carbon, oxygen, hydrogen, nitrogen and phosphorus predominate.

Question 3. Why are molecules of proteins, nucleic acids, carbohydrates and lipids considered as biopolymers only in a cell?
Molecules of proteins, nucleic acids, carbohydrates and lipids are polymers, as they consist of repeating monomers. But only in a living system (cell, organism) do these substances manifest their biological essence, possessing a number of specific properties and performing many important functions. Therefore, in living systems, such substances are called biopolymers. Outside the living system, these substances lose their biological properties and are not biopolymers.

Question 4. What is meant by the universality of biopolymer molecules?
Regardless of the level of complexity and the functions performed in the cell, all biopolymers have the following features:
there are few long branches in their molecules, but many short ones;
polymer chains are strong and do not spontaneously break apart;
are able to carry a variety of functional groups and molecular fragments that provide biochemical functional activity, i.e., the ability to carry out the biochemical reactions and transformations necessary for the cell in the medium of the intracellular solution;
have the flexibility sufficient to form very complex spatial structures necessary for the performance of biochemical functions, i.e. for the operation of proteins as molecular machines, nucleic acids as programming molecules, etc.;
C-H and C-C bonds of biopolymers, despite their strength, are simultaneously accumulators of electronic energy.
The main property of biopolymers is the linearity of polymer chains, since only linear structures are easily encoded and “assembled” from monomers. In addition, if the polymer thread has flexibility, then it is quite easy to form the desired spatial structure from it, and after the molecular machine built in this way is depreciated, broken, it is easy to disassemble it into its constituent elements in order to use them again. The combination of these properties exists only in carbon-based polymers. All biopolymers in living systems are capable of performing certain properties and performing many important functions. The properties of biopolymers depend on the number, composition, and arrangement of their constituent monomers. The possibility of changing the composition and sequence of monomers in the polymer structure allows the existence of a huge variety of biopolymer variants, regardless of the species of the organism. In all living organisms, biopolymers are built according to a single plan.

/ Chapter 1. Molecular level Task: §1.1. Molecular level general characteristic

Answer to Chapter 1. Molecular level Task: §1.1. Molecular level general characteristic
Ready-made homework (GDZ) Biology Pasechnik, Kamensky Grade 9

Biology

Grade 9

Publisher: Bustard

Year: 2007 - 2014

Question 1. What processes are investigated by scientists at the molecular level?

At the molecular level, the most important processes of the life of an organism are studied: its growth and development, metabolism and energy conversion, storage and transmission of hereditary information, variability.

Question 2. What elements prevail in the composition of living organisms?

There are more than 70-80 chemical elements in the composition of a living organism, but carbon, oxygen, hydrogen and nitrogen predominate.

Question 3. Why are molecules of proteins, nucleic acids, carbohydrates and lipids considered as biopolymers only in a cell?

Molecules of proteins, nucleic acids, carbohydrates and lipids are polymers, as they consist of repeating monomers. But only in a living system (cell, organism) do these substances manifest their biological essence, possessing a number of specific properties and performing many important functions. Therefore, in living systems, such substances are called biopolymers. Outside the living system, these substances lose their biological properties and are not biopolymers.

Question 4. What is meant by the universality of biopolymer molecules?

The properties of biopolymers depend on the number, composition, and arrangement of their constituent monomers. The possibility of changing the composition and sequence of monomers in the polymer structure allows the existence of a huge variety of biopolymer variants, regardless of the species of the organism. In all living organisms, biopolymers are built according to a single plan.