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MindMap Gallery High School Biology Chapter 2 Molecules that Make Up Cells
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High School Biology Chapter 2 Molecules that Make Up Cells
This is a mind map about the molecules that make up cells in Chapter 2 of high school biology, including that inorganic substances and proteins in cells are the main carriers of life activities.
Edited at 2023-11-25 20:14:40
- bacteria
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
- Plant asexual reproduction
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
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This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
High School Biology Chapter 2 Molecules that Make Up Cells
- bacteria
This is a mind map about bacteria, and its main contents include: overview, morphology, types, structure, reproduction, distribution, application, and expansion. The summary is comprehensive and meticulous, suitable as review materials.
- Plant asexual reproduction
This is a mind map about plant asexual reproduction, and its main contents include: concept, spore reproduction, vegetative reproduction, tissue culture, and buds. The summary is comprehensive and meticulous, suitable as review materials.
- Reproductive development of animals
This is a mind map about the reproductive development of animals, and its main contents include: insects, frogs, birds, sexual reproduction, and asexual reproduction. The summary is comprehensive and meticulous, suitable as review materials.
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- Outline
molecules that make up cells
elements and compounds in cells
elements that make up cells
There are more than 20 common chemical elements that make up cells.
Among the common chemical elements, those with large amounts include C, H, O, N, P, S, K, Ca, Mg and other elements, which are called macroelements.
Some elements are present in very small amounts, such as Fe, Mn, Zn, Cu, B, Mo, etc., which are called trace elements.
compounds that make up cells
The various elements that make up cells mostly exist in the form of compounds, such as water, proteins, nucleic acids, sugars, lipids, etc.
The most abundant compound in cells is water, and the most abundant organic compound is protein.
The contents of various compounds in cells of different biological tissues are different
Detect sugars, fats and proteins in biological tissues
Sugars (reducing sugars)
Inject 2ml of tissue sample liquid to be tested into the test tube
Inject 1ml of Fehling's reagent into the test tube (mix equal amounts of liquid A and liquid B before injecting)
Place the test tube into a large beaker filled with warm water at 50-65°C and heat for about 2 minutes
Observe the color changes that occur in the test tube
Note: water bath heating, ready for use
Essence: Reducing sugar reduces divalent copper to copper oxide, the color is brick red
Fat
Select the section from the petri dish, dip it with a brush and place it in the center of the slide
Put 2-3 drops of Sudan III dye on the peanut cotyledon slices and stain for 3 minutes.
Use absorbent paper to absorb the dye solution, then add 1-2 drops of 50% alcohol solution to wash away the floating color.
Use absorbent paper to absorb the alcohol around the peanut cotyledons, add a drop of distilled water, and cover with a coverslip to create a temporary mount.
protein
Inject 2ml of tissue sample liquid to be tested into the test tube
Inject 1ml of biuret reagent A solution into the test tube and shake well.
Inject 4 drops of biuret reagent B solution into the test tube and shake well.
Observe changes in color of tissue sample fluid
Note: Ready for use, add in sequence
Essence: Under alkaline conditions, Taibi reacts with the divalent copper in the biuret reagent to produce a purple complex.
inorganic substances in cells
water in cells
The water content of organisms varies with different species of organisms
Water is an important component of cells and the most abundant compound in living cells.
Water is a good solvent within cells, and many substances can be dissolved in water; many biochemical reactions within cells also require the participation of water.
The vast majority of cells in multicellular organisms must be immersed in a water-based liquid environment
The flow of water in the living body can transport nutrients to each cell, and at the same time, transport waste produced by each cell's metabolism to the excretory organs or directly excreted from the body.
Water exists in two forms in cells. Most of the water is free and can flow freely, which is called free water; part of the water is combined with other substances in the cell, which is called bound water.
Free water is a good solvent within cells. Under normal circumstances, the greater the proportion of free water in the cell, the more vigorous the metabolism of the cell.
The main form of bound water is that water is combined with proteins, polysaccharides and other substances, so that water loses fluidity and solubility and becomes a component of living organisms. Under normal circumstances, the more water is bound, the stronger the cells' ability to withstand adverse environments such as drought and cold.
inorganic salts in cells
Most inorganic salts in cells exist in the form of ions, and a few exist in the form of compounds
Mg is the element that makes up chlorophyll, and Fe is the element that makes up heme.
P is an important component of cell membranes and nuclei, and is also a component of many compounds essential to cells.
The lack of sodium ions in the human body can cause the excitability of nerve and muscle cells to decrease, eventually leading to muscle soreness, weakness, etc.
If calcium ion levels are too low, animals may develop convulsions and other symptoms
Certain inorganic salt ions in living organisms must be maintained in a certain amount, which is also very important for maintaining the acid-base balance of cells.
Many kinds of inorganic salts are important for maintaining the life of cells and organisms.
Sugars and lipids in cells
sugars in cells
Monosaccharide
Glucose is the main energy substance required for cell life activities
Glucose cannot be hydrolyzed and can be absorbed directly by cells. Sugars that cannot be hydrolyzed are simple sugars
disaccharide
It is formed by the dehydration and condensation of two molecules of monosaccharides, which generally need to be hydrolyzed into monosaccharides before they can be absorbed by cells.
polysaccharide
Most of the sugars in living organisms exist in the form of polysaccharides. Green plants produce starch through photosynthesis, which is present in plant cells as an energy storage substance in plants.
Starch ingested by the human body must be digested and broken down into glucose before it can be absorbed and utilized by cells.
lipids in cells
Lipids are present in all cells and are important organic compounds that make up cells and organisms.
The chemical elements of lipids are mainly C, H, and O. Some lipids also contain P and N.
The oxygen content in lipid molecules is much lower than that of sugars, and the hydrogen content is higher
Common lipids include fats, phospholipids and sterols. Their molecular structures are very different. They are usually insoluble in water but soluble in fat-soluble organic solvents, such as acetone, chloroform, ether, etc.
Fat
Fat is the most common lipid
Fat is a lipid formed by the reaction of three molecules of fatty acids and one molecule of glycerol, namely triacylglycerol (also known as triglyceride). Among them, the molecules of glycerol are relatively simple, but the types and molecular lengths of fatty acids are different. Most vegetable fats contain unsaturated fatty acids and are liquid at room temperature; most animal fats contain saturated fatty acids and are solid at room temperature.
Fat is a good energy storage material in cells and is also a good heat insulator.
The fat distributed around internal organs also has the function of buffering and decompressing, and can protect the organs
Phospholipids
The difference between phospholipids and fats is that one of the carboxyl groups (-OH) of glycerol is not combined with fatty acids to form esters, but is combined with phosphoric acid and other derivatives. Therefore, in addition to C, H, and O, phospholipids also contain P and even N.
Phospholipids are an important component of cell membranes and the membranes of various organelles.
sterol
Sterols include cholesterol, sex hormones, and vitamin D. Cholesterol is an important component of animal cell membranes, and it also participates in the transport of lipids in the blood in the human body; sex hormones can promote the development of human and animal reproductive organs and the formation of reproductive cells; vitamin D can effectively promote the absorption of calcium in the intestinal tract of humans and animals. and phosphorus absorption
Sugars and lipids in cells can be converted into each other. In addition to being used by cells, the excess glucose in the blood can be synthesized into glycogen and stored; if there is still excess glucose, it can be converted into fat and certain amino acids.
After the fat in food is digested and absorbed, it can be stored in the form of adipose tissue in subcutaneous connective tissue, etc.
Nucleic acids are carriers of genetic information
Types and distribution of nucleic acids
Deoxyribonucleic acid, referred to as DNA. The DNA of eukaryotic cells is mainly distributed in the nucleus, with a small amount of DNA also contained in mitochondria and chloroplasts.
Ribonucleic acid, abbreviated as RNA. RNA is mainly distributed in the cytoplasm
Nucleic acids are long chains of linked nucleotides
Nucleic acids are also biological macromolecules whose basic unit is nucleotides. Each nucleic acid molecule is a long chain connected by dozens or even hundreds of millions of nucleotides. A nucleotide is composed of a nitrogen-containing base molecule, a five-carbon sugar molecule, and a phosphate molecule. Nucleotides can be divided into deoxyribonucleotides and ribonucleotides based on the different five-carbon sugars.
DNA is made up of two strands of deoxynucleotides, and RNA is made up of one strand of ribonucleotides.
The genetic material of organisms is stored in DNA molecules, and the deoxynucleotide sequence of each individual's DNA has its own characteristics. The sequence of deoxyribonucleotides stores the genetic information of organisms. DNA molecules are biological macromolecules that store and transmit genetic information; the genetic material of some viruses is stored in RNA.
Nucleic acids are substances that carry genetic information in cells and play an extremely important role in the inheritance, mutation and protein biosynthesis of organisms.
Biological macromolecules use carbon chains as skeletons
Cells are made of a variety of elements and compounds. The basic unit of biological macromolecules is called a monomer. Each monomer has a carbon chain composed of several connected carbon atoms as its basic skeleton. Biological macromolecules are polymers connected by many monomers. Therefore, biological macromolecules also use carbon chains as their basic skeleton.
Biological macromolecules such as polysaccharides, proteins, and nucleic acids with carbon chains as the backbone form the basic framework of the cellular life building; sugars and lipids provide important energy sources for life activities; water and inorganic salts, together with other substances, are responsible for building cells, participate in cell life activities and other important functions
The content and proportion of compounds in cells are constantly changing, but remain relatively stable to ensure the normal progress of cell life activities.
Protein is the main carrier of life activities
The most abundant organic matter that makes up cells is protein. From a chemical perspective, proteins are also the most structurally complex and functionally diverse molecules currently known. Genetic information in the cell nucleus often needs to be expressed into proteins to function. Protein is the main carrier of life activities
Generally speaking, proteins are the basic components of cells and have the functions of participating in cell structure (many proteins are important substances that constitute the structure of cells and organisms) and catalysis (chemical reactions in cells cannot be separated from the catalysis of enzymes. Most enzymes They are all proteins), transportation, information transmission, immunity and other important functions. It can be said that all life activities of cells are inseparable from proteins.
The basic building blocks of protein – amino acids
Each amino acid contains at least one amino group and one carboxyl group, and both have an amino group and a carboxyl group attached to the same carbon atom. This carbon atom is also connected to a hydrogen atom and a side chain group, which is represented by R. The difference between various amino acids lies in the difference in the R group
Protein structure and its diversity
Protein is a biological macromolecule composed of amino acids as basic units. Amino acid molecules are first connected by binding to each other: the carboxyl group of one amino acid molecule is connected to the amino group of another amino acid molecule, and a molecule of water is removed at the same time. This combination method is called dehydration condensation. The chemical bond that connects two amino acid molecules is called a peptide bond. A compound formed by the condensation of two amino acids is called a dipeptide
A compound formed by the condensation of multiple amino acids and containing multiple peptide bonds is called a polypeptide. Polypeptides usually have a chain structure called a peptide chain. Because hydrogen bonds can be formed between amino acids, the peptide chain can twist and fold to form a protein molecule with a certain spatial structure.
Many protein molecules contain two or more peptide chains, which are bonded to each other through certain chemical bonds such as disulfide bonds. These peptide chains are not in a straight line or on the same plane, but form a more complex spatial structure.
In a cell, the number of amino acids that make up a protein may be tens of thousands. When amino acids form a peptide chain, the order of different types of amino acids changes. The way the peptide chain twists and folds and the spatial structure it forms varies greatly. Therefore, protein molecules structure and its diversity
Each protein molecule has a unique structure suitable for the function it assumes. If the amino acid sequence is changed or the spatial structure of the protein is changed, its function may be affected.
The same organism has different water contents at different stages of growth and development; the same organism has different water contents in different tissues and organs.