The main contents of cell theory

The process of establishing the cell theory

Plants have no system

Ecosystems are composed of communities and inorganic environments

Use of high-power microscopes: find, shift and transpose

No nucleus bounded by a nuclear membrane

A thin blue thread (chlamydia, mycoplasma, cyanobacteria, bacteria, actinomycetes), lactic acid bacteria, rickettsiae

Bacterial cell wall: peptidoglycan. Most types of bacteria are saprotrophic or parasitic. They are heterotrophs and have cell walls, cell membranes, and cytoplasm.

There is a nucleoid, no nuclear membrane, nucleolus, chromosomes, and nuclear pores; only ribosomes and naked circular DNA

Cyanobacteria: Chromococcus cyanobacteria, Oscillator cyanobacteria, Candida cyanobacteria, Nostoc cyanobacteria; have phycocyanin and chlorophyll, can carry out photosynthesis, and are autotrophs

There is a nucleus bounded by a nuclear membrane

Plants, animals, fungi (mushrooms, yeasts, molds), brown algae, Chlamydomonas, Volvox, green algae, red algae, amoeba, Euglena, Paramecium

Plant cell wall: cellulose and pectin; higher terrestrial fungal cell wall: chitin

There are formed nuclei, nuclear membranes, nucleoli, nuclear pores, chromosomes, and various organelles

There are more than 20 common ones

Fresh weight content: O>C>H>N Dry weight content: C>O>N>H

Macroelements: C, H, O, N, P, S, K, Ca, Mg Trace elements: Fe, Mn, B, Zn, Mo, Cu

Existence form: Most of the various elements that make up cells exist in the form of compounds, and a few exist in the form of ions.

Carbohydrates: C, H, O, lipids: C, H, O, (N, P) Protein: C, H, O, N, Nucleic acid: C, H, O, N, P

Content: water>protein>lipid>inorganic salt>saccharide and nucleic acid

The substance that accounts for the most fresh weight of the cell is water, the most abundant compound in the cell is water, and the most abundant organic compound is protein.

Reducing sugar Fehling's reagent (water bath heated to 50-65°C) = brick red precipitate Fat Sudan III dye=orange Protein Diuretic reagent = purple

free water

bound water

Existence form: Most inorganic salts in cells exist in the form of ions, and a small number exist in the form of compounds.

Function

Monosaccharides: glucose, fructose, galactose, ribose, deoxyribose

disaccharide

polysaccharide

Added sugar: no more than 50g, preferably less than 25g, excluding naturally occurring sugars

The more H and the less O, the more energy can be released

Fat (C, H, O)

Phospholipids (C, H, O, N, P)

Sterols (C, H, O)

Important substances that make up the structure of cells and organisms, called structural proteins

Able to regulate the body’s vital activities (insulin)

Most enzymes are proteins, and enzymes have catalytic functions

Transport function

Immune Function

There are 21 types of amino acids that make up protein

Amino acid molecular structure general formula

Reasons for structural diversity

protein denaturation

Salting out: adding neutral salt to the protein aqueous solution, as the salt concentration increases, the egg The phenomenon of white matter precipitation (reversible, peptide bonds and spatial structure remain unchanged)

Deoxyribonucleic acid (DNA): methyl green (green), mainly distributed in the nucleus, with a small amount distributed in mitochondria and chloroplasts

Ribonucleic acid (RNA): Parared (red), mainly distributed in the cytoplasm

the difference

Nucleotides are the basic building blocks of nucleic acids

A nucleotide is composed of one N-containing base molecule, one five-carbon sugar molecule, and one phosphate molecule.

DNA: a long chain of two deoxyribonucleotides linked together

RNA: a long chain of linked ribonucleotides, a

Nucleic acids are substances that carry genetic information in cells and play an extremely important role in genetic variation and protein biosynthesis of organisms.

Polysaccharides, proteins, and nucleic acids are all biological macromolecules

Carbon is the core element of life

Separates cells from the outside environment

Controlling the movement of substances in and out of cells

exchange information between cells

Irvington: Cell membranes are made of lipids

The lipids in cell membranes include phospholipids and cholesterol, with phospholipids being the most abundant.

Dutch Gott and Grendel: Phospholipid molecules in the cell membrane must be arranged into two consecutive layers

British Danielle and Davidson: May also have protein attached

Mainly composed of 50% lipid, 40% protein, and 2% to 10% carbohydrate

The more complex the function of the cell membrane, the greater the types and quantities of proteins.

Robertson: protein (dark) – lipid (light) – protein (dark)

Propose a hypothesis: 1 propose a hypothesis 2 revise and supplement 3 accept or deny

Mainly composed of phospholipid molecules and protein molecules

The phospholipid bilayer is the basic scaffolding of the membrane, with internal hydrophobicity and barrier function. Protein molecules are embedded in the phospholipid bilayer in different ways.

Functional features: Selective permeability Structural properties: Liquidity

There are sugar molecules on the outer surface of the cell membrane, which combine with protein molecules to form glycoproteins and combine with lipids to form glycolipids. These sugar molecules are called glycocalyx.

The sugar coat is closely related to functions such as cell surface recognition and intercellular information transmission.

Cell organelles: mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, ribosomes

Cytoplasm: sol-like cytoplasmic matrix

Differential centrifugation method: 1. Destroy the cell membrane 2. Place the homogenate into a centrifuge tube 3. Gradually increase the centrifugation rate

Chloroplasts: scattered in the cytoplasm, in the shape of flat, green ellipsoids or spheres

state of constant flow

Moss leaves, spinach leaves (lower epidermis with slightly mesophyll), sweet potato leaves, fresh black algae

Under light and room temperature conditions, increase the temperature, the flow rate will be faster, and the observation will be better.

The directions are not necessarily the same, but they are all circulations

isotope labeling

secreted protein

Organelle membrane, cell membrane, and nuclear membrane constitute the biofilm system of the cell.

The cell nucleus is the genetic information database and the control center of cell metabolism and genetics.

Nuclear membrane: a double membrane that separates the contents of the nucleus from the cytoplasm

Nucleolus: related to the synthesis of certain RNA and the formation of ribosomes. The more vigorous the protein synthesis of the cell, the larger the nucleolus will be.

Chromatin: Mainly composed of DNA and protein, DNA is the carrier of genetic information. (Chromatin and chromosomes are two states of the same substance in cells at different stages)

Nuclear pore: realizes frequent material exchange and information exchange between the nucleus and the cytoplasm (DNA cannot go out, RNA goes out, and proteins go in)

Physical model, conceptual model, mathematical model

Osmosis

Water moves in and out of mammalian red blood cells

Mature plant cell protoplasm

Hypothesis: The principle of water moving in and out of plant cells is osmosis

Materials: Purple onion scale leaves

Observation indicators: vacuole size, color, protoplasm layer position

Result record

Conclusion: Plant cells also absorb and lose water through osmosis.

plasmolysis

free diffusion

aiding proliferation

The transport of substances across membranes against concentration gradients requires the assistance of carrier proteins and also requires the consumption of energy released by chemical reactions within cells.

Small intestinal epithelial cells absorb amino acids and glucose in small intestinal fluid; the concentration of potassium ions in human red blood cells is 30 times higher than that in plasma; the concentration of potassium ions in charophyte cells is 63 times higher than that in the surrounding water environment

Counter concentration gradient, binding to specific parts of carrier protein (specificity, selectivity), energy

Influencing factors: type and quantity of carrier protein, energy (oxygen concentration, limitation: quantity of carrier protein) Concentration (limitations: carrier protein quantity, energy), temperature (carrier protein activity, activity of enzymes related to respiration, membrane fluidity)

Commonly found in animal, plant and microbial cells

Biological macromolecules such as proteins and polysaccharides, as well as some small molecules

Requires proteins on the membrane (receptor proteins)

Requires consumption of energy released by cellular respiration

Endocytosis: Receptor protein binding → cell membrane invagination to form vesicles → separation on the cell membrane → vesicles → entering the interior of the cell

Exocytosis: Formation of vesicles in the cell → Move to the cell membrane → Fusion with the cell membrane (fluidity of the cell membrane) → Expulsion of macromolecules (macromolecules pass through 0 layer of phospholipid molecules)

Spallanzani: A substance in gastric juice that digests food; Schwann, Germany: A substance in gastric gland secretions (pepsin)

Many chemical reactions are going on in cells every moment, collectively called cell metabolism. Cell metabolism is inseparable from enzymes.

The role of enzymes in cell metabolism

The nature of enzymes

Enzymes are organic substances with catalytic functions produced by living cells. Most enzymes are proteins and a few are RNA.

Enzymes are highly efficient

Enzymes are specific

Enzyme action conditions are milder

Molecular structure abbreviation: A——P～P～P

Two adjacent phosphate groups are negatively charged and repel each other → the chemical bond is unstable → the terminal phosphate group has a higher transfer potential → when ATP is hydrolyzed by the enzyme, the terminal phosphate group carries energy with other molecules combine → the latter changes

The process of ATP hydrolysis is the process of releasing energy. The energy released by the hydrolysis of 1 mol ATP is as high as 30.54kJ, so ATP is a high-energy phosphate compound.

ATP is hydrolyzed into the more stable ADP (adenosine diphosphate) and Pi (free phosphate)

ADP can accept energy and combine with Pi to re-form ATP.

Not a reversible reaction

This mutual conversion of ATP and ADP occurs all the time and is in dynamic balance. It is the same in all cells, which reflects the unity of the biological world.

ADP synthesizes ATP energy

ATP → Enzyme → ADP Pi Energy

ADP Pi Energy→Enzyme→ATP

It is precisely because of the energy "currency" of ATP that the energy requirements of various life activities of cells can be met in a timely and continuous manner.

ATP powers active transport