"Proteins and their functions" - 1 g of protein is equivalent to 17.6 kJ. The concept of proteins. Transport function of proteins. Construction material. Energy function. Transformation of proteins in the body. Chemical properties of proteins. protective function. Secondary structure Tertiary structure Quaternary structure.

"Proteins substance" - Dietary proteins. Quaternary. Make up the cytoskeleton of the cell. Quaternary structure. They have only a few proteins. The coil is held due to the bonds that arise between the AA radicals. Consist of a large number of AK. energy proteins. Insoluble proteins are fibrillar. Used by the body for movement.

"Protein Biosynthesis Biology" - W. The main function of ribosomes is the synthesis of proteins. Such a complex is called a polysome. I know and can: Translation is the translation of a nucleotide sequence into a protein amino acid sequence. D. Ribosomes are very small cell organelles formed by ribonucleic acids and proteins. "We are all heirs of DNA."

"Protein biosynthesis" - 7. Contents. Biosynthesis of proteins in a living cell. 9. 6. 3. References. 10. 5. Scheme of plant and animal cells. Participants in the biosynthesis of protein molecules. Introduction. 12.

"Biosynthesis of proteins" - Test yourself. The value of proteins. Translation (lat. transfer, translation). Synthesis of a polypeptide chain on a ribosome. 6. A segment of DNA is given: C-G-A-T-T-A-G-C-G-G-A-A-C-A-C. Transcription Broadcast. Content. Energy of biosynthesis. Lesson topic: Protein biosynthesis.

“Protein Functions” - 6. The signaling function of proteins is very important for cell life. The motor function is performed by: special contractile proteins in flagella, cilia, muscles. Able to attach or give hydrogen ions, maintaining a certain pH level. One of the most important functions of proteins. For example, insulin regulates blood sugar levels.

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Presentation on the topic: Functions of proteins

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Proteins are amphoteric compounds that combine basic and acidic properties determined by amino acid radicals. There are acidic, basic and neutral proteins. The ability to donate and attach H+ is determined by the buffer properties of proteins, one of the most powerful buffers is hemoglobin in erythrocytes, which maintains blood pH at a constant level. There are soluble proteins, there are insoluble proteins that perform mechanical functions (fibroin, keratin, collagen). There are proteins that are unusually chemically active (enzymes), there are chemically inactive ones. There are resistant to various environmental conditions and extremely unstable. External factors (changes in temperature, salt composition of the environment, pH, radiation) can cause a violation of the structural organization of the protein molecule. 1. Properties of proteins

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5. The process of losing the three-dimensional conformation inherent in a given protein molecule is called denaturation. The cause of denaturation is the breaking of bonds that stabilize a particular protein structure. At the same time, denaturation is not accompanied by the destruction of the polypeptide chain. A change in the spatial configuration leads to a change in the properties of the protein and, as a result, makes it impossible for the protein to perform its biological functions. Denaturation can be: reversible, the process of restoring the protein structure after denaturation is called renaturation. If the restoration of the spatial configuration of the protein is impossible, then denaturation is called irreversible. 6. Destruction of the primary structure of a protein molecule is called degradation. 1. Properties of proteins

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What proteins are called acidic? Proteins with more acidic amino acids that lower the pH. What proteins are called neutral? Proteins in which the same number of carboxyl and amino groups. Why are proteins powerful buffer systems? Able to attach or give hydrogen ions, maintaining a certain pH level. What is protein denaturation? The process of losing the three-dimensional conformation inherent in a given protein molecule is called denaturation. What is renaturation? The process of restoring the protein structure after denaturation is called renaturation. Give examples of soluble and insoluble proteins: Soluble (blood plasma proteins - fibrinogen, prothrombin, albumin, globulins), insoluble proteins that perform mechanical functions (fibroin, keratin, collagen). Give examples of proteins that are resistant to external influences: Fibroin is a web protein, keratin is a hair protein, collagen is a tendon protein. Let's summarize:

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Due to the complexity, variety of forms and composition, proteins play an important role in the life of the cell and the organism as a whole. One of the most important is construction. Proteins are involved in the formation of cellular and extracellular structures: they are part of cell membranes, wool, hair, tendons, vessel walls, etc. 2. Functions of proteins

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2. Transport. Some proteins are able to attach various substances and carry them to various tissues and organs of the body, from one place in the cell to another. For example, the blood protein hemoglobin transports O2 and CO2; The composition of cell membranes includes special proteins that provide an active and strictly selective transfer of certain substances and ions from the cell to the external environment and vice versa. 2. Functions of proteins

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3. Regulatory. A large group of body proteins is involved in the regulation of metabolic processes. Such proteins are hormones - biologically active substances released into the blood by endocrine glands (hormones of the pituitary gland, pancreas). For example, the hormone insulin regulates blood sugar levels by increasing the permeability of cell membranes to glucose and promotes glycogen synthesis. 4. Protective. In response to the penetration of foreign proteins or microorganisms (antigens) into the body, special proteins are formed - antibodies that can bind and neutralize them. Fibrin, formed from fibrinogen, helps to stop bleeding. 2. Functions of proteins

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5. Motor. Special contractile proteins (actin and myosin) are involved in all types of cell and organism movement: the formation of pseudopodia, the flickering of cilia and the beating of flagella in protozoa, muscle contraction in multicellular animals, the movement of leaves in plants, etc. 2. Functions of proteins

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6. The signaling function of proteins is very important for cell life. Molecules of proteins are embedded in the surface membrane of the cell, capable of changing their tertiary structure in response to the action of environmental factors. This is how signals from the external environment are received and commands are transmitted to the cell. 2. Functions of proteins

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7. Spare. Thanks to proteins, certain substances can be stored in the body in reserve. For example, during the breakdown of hemoglobin, iron is not excreted from the body, but is stored in the body, forming a complex with the ferritin protein. Storage proteins include egg proteins and milk proteins. 8. Energy. Proteins are one of the sources of energy in the cell. With the breakdown of 1 g of protein to the final products, 17.6 kJ is released. First, proteins break down to amino acids, and then to the final products - water, carbon dioxide and ammonia. However, proteins are used as an energy source when others (carbohydrates and fats) are used up. 2. Functions of proteins

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9. Catalytic. One of the most important functions of proteins. The rate of enzymatic reactions is tens of thousands (and sometimes millions of times) higher than the rate of reactions involving inorganic catalysts. For example, hydrogen peroxide decomposes slowly without catalysts: 2H202 → 2H20 + 02. In the presence of iron salts (catalyst), this reaction proceeds somewhat faster. Catalase enzyme for 1 sec. splits up to 100 thousand H202 molecules. The mass of the enzyme is much greater than the mass of the substrate, that part of the enzyme molecule that interacts with the substrate molecule is called the active site of the enzyme. 2. Functions of proteins

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Enzymes are globular proteins; according to their structural features, enzymes can be divided into two groups: simple and complex. Simple enzymes are simple proteins, i.e. consist only of amino acids. Complex enzymes are complex proteins, i.e. in their composition, in addition to the protein part, there is an organic compound of a non-protein nature - coenzymes: metal ions or vitamins. 2. Functions of proteins

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Enzymes are specific - they can catalyze one type of reaction - a certain substrate molecule enters the active center. Since almost all enzymes are proteins (there are ribozymes, RNA that catalyze some reactions), their activity is highest under physiologically normal conditions: most enzymes work most actively only at a certain temperature, pH, the rate depends on the concentration of the enzyme and substrate. When the temperature rises to a certain value (on average, up to 50°C), the catalytic activity increases (for every 10°C, the reaction rate increases by about 2 times). 2. Functions of proteins

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The building function of proteins is manifested: Proteins are part of all cell membranes and cell organelles. The walls of blood vessels, cartilage, tendons, hair and nails are mainly composed of protein. The motor function is performed by: special contractile proteins in the flagella, cilia, muscles. The transport function of proteins is manifested: Transport proteins in the outer membrane of cells carry various substances from the environment to the cytoplasm, hemoglobin myoglobin transport oxygen. The protective function of proteins is manifested in the fact that: Antibodies produced by lymphocytes block foreign proteins; fibrin and thrombin protect the body from blood loss. Regulatory function of proteins: Protein hormones (hormones of the pituitary gland, pancreas) are involved in growth, reproduction and other vital processes. For example, insulin regulates blood sugar levels. Let's summarize:

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Signaling function: Proteins are embedded in the cell membrane that can change their tertiary structure in response to environmental factors. This is how signals are received from the external environment and information is transmitted to the cell. Energy function: With the complete breakdown of 1 g of protein to final products, 17.6 kJ of energy is released. However, proteins are rarely used as an energy source. Catalytic function: Proteins - enzymes are capable of accelerating biochemical reactions in the cell by tens and hundreds of millions of times. Coenzyme: A non-protein compound that is part of an enzyme. Various organic substances, usually vitamins, and inorganic substances, ions of various metals, act as coenzymes. Let's summarize:

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"The structure and functions of proteins" Chemistry teacher MBOU secondary school No. 81 Krasnodar Itskovich T. Ya

The elemental composition of proteins C (carbon) - 50-55%; O (oxygen) - 21-24%; N (nitrogen) - 15-17% (≈ 16%); H (hydrogen) - 6-8%; S (sulfur) - 0-2%. Nitrogen is a constant component of proteins and its amount can be used to determine the protein content in tissues. The content of proteins in human organs is on average 18-20% of the raw mass of the tissue. In terms of dry residue - muscles - up to 80%, heart - 60%, liver - 72%, lungs, spleen - 82 - 84%. Amino acids - protein monomers Most proteins contain 20 different amino acids out of about 170 known. As from 33 letters of the alphabet we can make an infinite number of words, so from 20 amino acids - an infinite number of proteins. There are up to 100,000 proteins in the human body.

Amino acids Non-essential Non-essential amino acids can be synthesized in the body. The need of the body is carried out due to the intake of food proteins. The essential amino acids include alanine, asparagine, aspartic acid, glycine, glutamine, glutamic acid, tyrosine, cysteine, cystine, and others. phenylalanine. For children, arginine and histidine are also indispensable. They cannot be synthesized in the body.

Amino acid - amphoteric compound Primary structure - a specific sequence of amino acid residues in the polypeptide chain. The bonds between amino acids are covalent, and therefore very strong NH 3- AMINO GROUP (base properties - COOH CARBOXY GROUP (properties of acids Primary protein structure

Secondary structure of a protein The secondary structure is a conformation of a polypeptide chain, fixed by many hydrogen bonds between the N-H and C=O groups. Secondary structure models - a-helix. Tertiary structure - the shape of a twisted spiral in space Tertiary structure of a protein

Quaternary protein structure Quaternary structure - aggregates of several protein macromolecules (protein complexes) Protein denaturation after the impact of the denaturing agent is removed, the protein restores its activity. denaturation Denaturation of proteins is the loss of their biological properties (catalytic, transport, etc.) by proteins due to changes in the structure of the protein molecule

The history of the discovery of proteins For the first time, the term protein (albumineise) in relation to all fluids of the animal body was used, by analogy with egg white, by the French physiologist F. Quesnay in 1747, and it was in this interpretation that the term entered the Encyclopedia in 1751. Diderot and J. D "Alembert. John Dalton - English chemist (September 6, 1766 - July 27, 1844 In 1803, he gives the first formulas of proteins - albumin and gelatin - as substances containing nitrogen Joseph Louis Gay-Lussac - French chemist (12/6/1778 -05/09/1850 Conducts chemical analyzes of proteins - blood fibrin, casein and notes the similarity of their elemental composition Henri Braconnot - French chemist (05.29. 1780 - 01.13.1855) First isolated (1820) amino acids glycine and leucine from a protein hydrolyzate. Gerrit Jan Mulder Dutch organic chemist who described the chemical composition of proteins and was awarded the Nobel Prize in Physiology or Medicine in 1910 for one of the first theories of protein structure. spruce blocks" in the synthesis of proteins.

The history of the discovery of proteins Danilevsky Alexander Yakovlevich - Russian biochemist 1838–1923 Author of the theory of the polypeptide structure of proteins Nikolai Nikolaevich LYUBAVIN - Russian chemist Developed a method for the synthesis of amino acids Linus Karl Pauling - American chemist The first scientist who was able to successfully predict the secondary structure of proteins Frederick Senger - English biochemist Twice winner Nobel Prize in Chemistry: 1958 - "for his work on the determination of the structures of proteins, especially insulin", 1980 - "for his contribution to the establishment of basic sequences in nucleic acids"

Functions of proteins in the body Slide text

Structural function Structural proteins of the cytoskeleton, like a kind of armature, give shape to cells and many organelles and are involved in changing the shape of cells. Collagen and elastin are the main components of the intercellular substance of connective tissue (for example, cartilage), and hair, nails, bird feathers, and some shells are made up of another structural protein, keratin.

Transport function The transport protein hemoglobin carries oxygen from the lungs to other tissues and carbon dioxide from tissues to the lungs, as well as proteins homologous to it, found in all kingdoms of living organisms. .

Protective function of the liver - "cleanses" the blood, that is, rearranges the toxin so that it can leave the body. Chemical protection. The binding of toxins to protein molecules can provide their detoxification. A particularly important role in detoxification in humans is played by liver enzymes that break down poisons or convert them into a soluble form, which contributes to their rapid removal from the body. Immune protection. Proteins that make up blood and other biological fluids are involved in the body's defense response to both damage and attack by pathogens.

Energy function Proteins are first broken down into amino acids, and then into final products - water, carbon dioxide and ammonia. However, proteins are used as an energy source only when other sources (carbohydrates and fats) are used up.

Option 2. 1. How many amino acids are essential for humans? A) there are no such amino acids; b) 20; at 10 o'clock; d) 7. 2. Between what groups of amino acids is a peptide bond formed? A) between carboxyl groups of adjacent amino acids; B) between the amino groups of neighboring amino acids; C) between the amino group of one amino acid and the carboxyl group of another. D) between the amino group of one amino acid and the radical of another. 3. What is the structure of a hemoglobin molecule? A) primary b) secondary; c) tertiary; d) quaternary. 4. The primary structure of the protein is supported by bonds: a) peptide; b) hydrogen; c) disulfide; d) hydrophobic. 5. The secondary structure of a protein is determined by: a) spiralization of the polypeptide chain; b) the spatial configuration of the polypeptide chain; c) the number and sequence of amino acids of the spiralized chain; G). spatial configuration of the helical chain. 6. The tertiary structure of the protein is mainly supported by bonds: a) ionic; b) hydrogen; c) disulfide; d) hydrophobic. 7. Name the protein that was first artificially synthesized: a) insulin; b) hemoglobin; c) catalase; d) interferon. COMPOSITION AND FUNCTIONS OF PROTEINS. Option 1. 1. What organic substances in the cell are in first place in terms of mass? A) carbohydrates; b) proteins; c) lipids; d) nucleic acids. 2. How many amino acids does the whole variety of proteins form? A) 170; b) 26; in 20; d) 10. 3. The primary structure is determined by amino acid residues: a) number; b) sequence; c) number and sequence; d) views. 4. The secondary structure of the protein is mainly supported by bonds: a) peptide; b) hydrogen; c) disulfide; d) hydrophobic. 5. The tertiary structure of a protein is determined by: a) spiralization of the polypeptide chain; b) the spatial configuration of the helical polypeptide chain; c) the connection of several polypeptide chains; d) spiralization of several polypeptide chains. 6. The following bonds do not take part in maintaining the quaternary structure of a protein: a) peptide bonds; b) hydrogen; c) ionic; d) hydrophobic. 7. Physical - chemical and biological properties of the protein is completely determined by the structure: a) primary; b) secondary; c) tertiary; d) quaternary.

Reference abstract on the topic “Proteins. The structure and functions of proteins"

PROTEINS – C,H,O,N….S…….Fe MONO – AMINO ACID 20 – MAGICAL! ∞ LEVELS: 1-ary peptide (last A/K) 2nd H-bonds 3rd hydrophobic H-bonds -S-S-bonds 4th Hb 11

DENATURATION 2,3,4 1! 1 Functions: 1. Catalytic (enzymes) 2. Protective (immunoglobulin) 3. Signal (rhodopsin) 4. Transport (hemoglobin) 5. Structural (collagen, keratin) 6. Motor (actin, myosin) 7. E (1gr.- 17.6 kJ) 8. Regulatory (insulin, histones) 9. Storage (casein) renaturation, irreversible reference summary on the topic “Proteins. The structure and functions of proteins"

Conclusion Proteins are key players in any living system. Proteins are polymers made up of 20 different amino acids. Each protein assembles into a unique three-dimensional structure defined by its amino acid sequence. The protein has a hierarchical structure of its form. The three-dimensional structure of a protein is closely related to its function. Predetermining the three-dimensional shape of a protein will be a huge breakthrough in computational biology.

Functions of proteins
1. Structural function.
Proteins are part of all
cellular
organelle:
membranous - plasmalemma,
nuclear
shell,
endoplasmic
or
reticular
network
(ER),
Golgi complex, lysosomes,
peroxisomes,
vacuole,
mitochondria, plastids and
non-membrane - chromosomes,
ribosomes, cell center
(centrioles),
cilia
and
flagella, microfilaments.

2. Catalytic function.
All enzymes are proteins. This function ceased in 1982
be considered unique. It turned out that some RNAs also
have catalytic activity. They are called
RNAzymes.
3. Protective function (for now
is unique).
Antibodies
This
proteins.
Immunoglobulins stick together
antigens
and
formed
precipitate

4. Regulatory function.
At the cellular level: proteins - repressors and transcription activators.
At the organism level: some hormones
proteins.
For example, insulin is a hormone produced by the pancreas.
Regulates the passage of glucose through the plasmalemma. At
insufficient secretion of insulin develops
heavy
disease
sugar
diabetes.
Somatotropin is a growth hormone. Formed in the front
share
pituitary.
There
same
formed
and
adrenocorticotropic hormone (ACTH). He acts
on the adrenal cortex, regulating the synthesis of steroid
hormones.

5. Energy transformation.
The retinal proteins rhodopsin and retinene transform
light energy into electrical energy. Actin-myosin
complexes in the muscles convert the energy of chemical
links to mechanical.
6. Transport function.
Hemoglobin
carries out
transport
O2
CO2.
Transferrin
transport
gland.
Permease systems are membrane proteins that
transport polar compounds across the membrane
and against the concentration gradient.

7. Energy function.
11 of the 20 amino acids that make up proteins
the human body "burn" with the release of energy.
These are non-essential amino acids. They may be
synthesized in the cell from cleavage products
carbohydrates and lipids
8. Buffer function.
Any protein is an amphoteric polyelectrolyte. Squirrels
contribute to the maintenance of certain pH values
in different compartments of the cell, providing this
compartmentalization.

9. Nutritional function.
a) Supply of essential amino acids. A person has 9 of
20 amino acids cannot be synthesized in
body. They must come from outside.
The concept of "essential and irreplaceable amino acids" is species-specific and applies only to animals and
mushrooms.
b) Spare proteins for the development of the embryo and
feeding the baby. For example, casein is a protein
milk, ovalbumin - egg white, gliadin - protein
grains of wheat.

AMINO ACID

The formula is correct for 19 of
20
amino acids,
found in proteins. AT
composition of proteins other than these
19 amino acids included
one imino acid proline.
in all amino acids
available
amino group.
Hence the name - "α
amino acids".
In nature, there are two forms of stereoisomers: L (left-handed) and
D (dextrorotatory). In addition to L - amino acids included in proteins, in
the body also has D-amino acids, which are not included in proteins.
The general formula of an amino acid is shown in the figure.

PROTEINOGENIC AMINO ACIDS ARE CLASSIFIED:
- according to the structure of the side chain (R-groups)
aliphatic, aromatic and heterocyclic amino acids;
- by additional groups in the radical
diaminomonocarboxylic (two NH2 groups and one COOH group),
monoamine dicarboxylic (one
NH2 group and two COOH groups),
hydroxyamino acids, sulfur-containing, imino acids (NH)
- according to the position of the isoelectric point
neutral, basic and acidic
- according to the polarity of R-groups, i.e. ability of R-groups to interact with water
under appropriate intracellular pH conditions (pH near 7.0)
with non-polar or hydrophobic R-groups, polar but not
charged R-groups, negatively charged R-groups and
positively charged R-groups
- according to the ability to synthesize in the animal body
and replaceable and irreplaceable.

1. Non-polar or hydrophobic radicals.
Aliphatic - alanine, valine, leucine, isoleucine.
Sulfur containing methionine. Aromatic - phenylalanine,
tryptophan. Proline imino acid.
2. Polar but uncharged radicals. Glycine.
hydroxyamino acids
serine,
threonine,
tyrosine.
containing
sulfhydryl
group
cysteine.
Containing an amide group: asparagine, glutamine.
3. Negatively charged radicals. Aspartic
acid, glutamic acid.
4. Positively charged radicals.
Lysine, arginine, histidine.

Peptide bond

Polypeptide

H2N- CH - CO - (NH - CH - CO) n - NH - CH - COOH
│
│
│
R
R
R
(N-terminus)
(C-end)
PRIMARY STRUCTURE is linear, represented
sequence
amino acids,
connected by peptide bonds

SECONDARY STRUCTURE
The secondary structure is spatial, it
formed only by hydrogen bonds of the pepid backbone
between C=O and N-H groups of different amino acids.
Allocate α-helix, β-folded sheet and collagen
spiral

Classification by type of building
fibrillar proteins
Globular proteins
Membrane proteins

Types of location of the secondary structure in globules

TERTIARY STRUCTURE
The tertiary structure of a protein is a spatial
the conformation of a polypeptide having a secondary structure,
and due to interactions between radicals.
THE TERTIARY STRUCTURE IS COMPLETELY SET BY THE PRIMARY

F. Engels

Topic: "Protein Functions"

The purpose of the lesson:

1. Find out if proteins are really "the basis of life"
2. Prove that proteins are the "basis of life" based on the study of the properties and functions of proteins

1. The structure of proteins
2. Classification and properties of proteins

Biological warm-up 1. Structure of a protein molecule

1. High molecular weight organic compound consisting of repeating units
2. Violation of the natural structure of the protein
3. Repeating links - simple molecules
4. Biopolymers; monomers are amino acids
5. Strong covalent polar; between amino acids in a protein
6. Reversible denaturation
7. Violation of the primary structure of the protein

1. Why do doctors recommend taking antipyretic drugs if the patient's temperature exceeds 38 ° C?
2. Why does a chicken never appear from a boiled egg?
3. Why do workers of chemical industries, in case of poisoning with salts of heavy metals (Cu, Pb, Pg), give milk to the victims? Give a hygienic justification for studying protein functions?

1. What are enzymes?
2.What are their functions?
3. What is the essence of a catalytic reaction?
4. What is the difference between an enzyme and a catalyst?
5. How do factors affect the work of the enzyme?
6. What did you learn about the catalase enzyme?

The substance that an enzyme acts on is called substrate. Substances resulting from an enzymatic reaction are called products reactions

Search mission

1. Keynote

2. Textbook for grade 10 (profile) - pp. 98-99

3. Reference manual - pages 107 - 110

Construction
Receptor
Regulatory
Transport
Protective
toxins
Motor
Energy
Reserve
catalytic

1. Structural- proteins are involved in the formation of cellular and extracellular structures, for example, they are part of cell membranes, hair (keratin), tendons (collagen), etc.

2. Signal (receptor) - protein molecules are embedded in cell membranes that can change their tertiary structure in response to environmental factors and thus transmit signals to the cell

3. Regulatory Some hormones are protein in nature. For example, insulin, which regulates blood glucose levels

4. Transport Cell membranes contain special transport proteins that can bind certain substances (glucose, amino acids) and transport them into cells. Hemoglobin transports oxygen and partially carbon dioxide

5. Protective Immunoglobulins (antibodies) have the ability to recognize foreign proteins or microorganisms that have entered the body and neutralize them. Fibrinogen and prothrombin are involved in the process of blood clotting and protect the body from blood loss.