3.2.2.1.1. Acylglycerides

Acylglycerides (or fats)

The acylglycerides or fats or are saponifiable lipids formed by the esterification of one, two or three molecules of fatty acids with a glycerol molecule (propanetriol), releasing one, two or three water molecules. They are also called glycerides or glycerolipids or acylglycerols.

Three types are distinguished, according to the number of fatty acids that make up the acylglyceride molecule:

Monoacylglycerides: contain a fatty acid molecule.
Diacylglycerides: with two fatty acid molecules.
Triacylglycerides: with three fatty acid molecules.

By Iacopo Leardini. Versión en español de Alejandro Porto. (File:Trigliceridi.gif) [CC0], via Wikimedia Commons

Fats, at room temperature, can be:

Oils: when the acylglyceride has at least one unsaturated fatty acid, its state is liquid at room temperature. For example, olive oil is an ester of three oleic acids with a glycerin.
Tallow: when all the fatty acids are saturated, the acylglyceride is solid at room temperature. For example, beef, horse or goat fat.
Butters: when the acylglyceride is semisolid (short chain fatty acids), such as pork fat.

In cold-blooded animals and vegetables there are oils, and in warm-blooded animals there are tallow or butters.

The acylglycerides are not soluble in water because the groups hydroxyl (-OH) of glycerol, polar , are linked by an ester linkage to the groups carboxyl (-COOH) of fatty acids. The triacylglycerols are considered neutral fats because they are nonpolar and insoluble in water. The monoacylglycerides and diacylglycerides have weak polarity by the radicals hydroxyl left free in the glycerin.

The triacylglycerols constitute a form of energy storage in animal cells and plant. They can be stored in large quantities in confined spaces without disturbing cellular homeostasis. That is why it is a more effective form of energy reserve than that of carbohydrates.

Acylglycerides when they react with bases, produce soap by saponification.

The saponification is the formation of soap from saponifiable lipids by chemical reaction between a triacylglycerol and a base (NaOH or KOH). In the reaction, glycerin is released and three molecules of sodium or potassium salts (soaps) corresponding to fatty acids are formed.

Animated image: Formation of a triglyceride.

Video: What is fat?. The type of fat you eat is more important in your diet than the amount.

Functions of acylglycerides

Acylglycerides are the main energy reserve in both animals and plants. In plants, they accumulate in vacuoles, and in animals, in adipocytes, specialized cells of adipose tissue.

Although starch and glycogen are the main sources of energy due to their rapid mobilization as they are soluble in water, fats provide much more energy (9 Kcal / g).

Acylglycerides also act as thermal insulators. For example, by forming a layer of fat under the skin of some homeothermic animals that live in cold climates to be able to live with low temperatures. Other hibernators accumulate fat under the skin and around organs to use as food during the hibernation period.

They are good mechanical shock absorbers. They absorb the energy of blows and, therefore, protect sensitive structures or structures that suffer continuous friction.

Fundamental ideas about fats or acylglycerides

The triglycerides, fats or triacylglycerols, are formed by the esterification of one molecule of glycerol with three molecules of fatty acids, which may be identical or different.

The triacylglyceride is formed by the union of the carboxyl groups (–COOH) of three fatty acids with the three hydroxyl groups (-OH) of a glycerol molecule, forming three ester bonds and the release of three water molecules

Depending on how these fatty acids are, triacylglycerides can be:

Saturated fats, when the fatty acids are saturated, without presenting double bonds between the carbons of the hydrocarbon chain.
Monounsaturated fats, when the fatty acids are monounsaturated, containing a double bond.
Polyunsaturated fats, when the fatty acids are polyunsaturated, containing several double bonds.

The main function of triacylglycerides is that of energy reserve, in animals and plants. They also act as thermal insulators, as a food store and as mechanical protection for certain organs, such as the heart and kidneys.

Triacylglyceride can be saponified when subjected to alkaline hydrolysis with NaOH and KOH solutions, producing soap, a sodium or potassium salt (stearate), and glycerin, which is an alcohol.

Have you ever asked in college entrance exams for the difference in triglycerides and phosphoglycerides or phospholipids:

Triglycerides: formed by the union of glycerin and three fatty acids.
Phosphoglycerides or phospholipids: formed by the union of glycerin, two fatty acids, phosphoric acid and an amino alcohol (serine).

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Skip navigation Biology 2nd Baccalaureate Biology 2nd Bac. 1. Bioelements and biomolecules. Water and mineral salts 1.1. Chemical bonds in biology 1.1.1. Intramolecular bonds 1.1.1.1. Covalent bond 1.1.1.2. Ionic bond 1.1.2. Intermolecular bonds 1.1.2.1. Van der Waals forces 1.1.2.2. Hydrogen bonds 1.2. The chemical basis of life: inorganic and organic components 1.2.1. Primary bioelements 1.2.2. Secondary bioelements 1.2.3. Trace elements 1.3. The immediate principles or biomolecules 1.3.1. Water 1.3.1.1. Chemical structure of water 1.3.1.2. Properties and functions of water 1.3.2. Mineral salts 1.3.2.1. Functions of salts in solution 1.3.2.2. Colloidal solutions and dispersions 1.3.2.3. Properties of colloidal dispersions 1.3.2.4. Diffusion, osmosis and dialysis 1.3.2.4.1. Diffusion 1.3.2.4.2. Osmosis 1.3.2.4.3. Dialysis 1.4. Bibliography 2. Glucides 2.1. Glucid concept 2.2. Classification of carbohydrates 2.3. Monosaccharides 2.3.1. Trioses 2.3.1.1. Spatial isomerism or stereoisomerism 2.3.2. Tetroses 2.3.3. Pentoses 2.3.3.1. Monosaccharide cyclization 2.3.4. Hexoses 2.4. The N-glucosidic and O-glucosidic bonds 2.4.1. Substances derived from monosaccharides 2.5. Disaccharides 2.6. Polysaccharides 2.6.1. Homopolysaccharides 2.6.1.1. Reserve homopolysaccharides 2.6.1.2. Structural homopolysaccharides 2.6.2. Heteropolysaccharides 2.6.3. Heterosides 2.7. General functions of glucides 2.8. Bibliography 3. Lipids 3.1. Lipid concept 3.2. Classification of lipids 3.2.1. Fatty acids 3.2.1.1. Saturated and unsaturated fatty acids 3.2.1.2. Chemical properties of fatty acids 3.2.1.3. Physical properties of fatty acids 3.2.1.4. Fatty Acid Functions 3.2.2. Saponifiable lipids or with fatty acids 3.2.2.1. Simple lipids 3.2.2.1.1. Acylglycerides 3.2.2.1.2. Cerides 3.2.2.2. Complex lipids 3.2.2.2.1. Phospholipids 3.2.2.2.2. Glycolipids 3.2.3. Unsaponifiable lipids or without fatty acids 3.3. Lipid functions 3.4. Bibliography 4. Proteins 4.1. Introduction to proteins 4.2. Amino acids 4.2.1. Classification of amino acids 4.2.2. Properties of amino acids 4.3. The peptide bond 4.4. Protein 4.4.1. Protein structure 4.4.1.1. Primary structure of proteins 4.4.1.2. Secondary structure of proteins 4.4.1.3. Tertiary structure of proteins 4.4.1.4. Quaternary structure of proteins 4.4.2. Protein properties 4.4.3. Classification of proteins 4.4.3.1. Holoproteins 4.4.3.2. Heteroproteins 4.4.4. Protein functions 4.5. Enzymes 4.5.1. Structure of enzymes 4.5.2. The active center of enzymes 4.5.3. General Mechanism of Enzyme Catalysis 4.5.4. Regulation of enzyme activity 4.5.5. Allosteric enzymes 4.5.6. Nomenclature and classification of enzymes 4.6. The vitamins 4.6.1. Fat-soluble vitamins 4.6.2. Water soluble vitamins 4.7. Bibliography 5. Nucleotides and nucleic acids 5.1. The chemical composition of nucleic acids 5.1.1. Components of nucleic acids 5.1.2. Concept, types and functions of nucleic acids 5.1.3. Nucleosides 5.1.4. Nucleotides 5.1.4.1. Nucleotide functions 5.1.5. Nucleic acids 5.2. Deoxyribonucleic acid (DNA) 5.2.1. DNA structure 5.2.1.1. Primary structure of DNA 5.2.1.2. Secondary structure of DNA 5.2.1.3. Tertiary structure of DNA 5.2.1.3.1. Tertiary structure of DNA in prokaryotes 5.2.1.3.2. Tertiary structure of DNA in eukaryotes 5.2.1.4. Quaternary structure of DNA 5.2.2. DNA types 5.2.3. Genetic material: chromatin and chromosomes 5.2.3.1. Karyotype and karyogram 5.3. Ribonucleic acid (RNA) 5.3.1. RNA types 5.3.1.1. Transfer RNA 5.3.1.2. Messenger RNA 5.3.1.3. Ribosomal RNA 5.3.1.4. Nucleolar RNA 5.3.1.5. Small nuclear RNA 5.3.2. Functions of ribonucleic acids 5.4. Bibliography 6. Cell morphology 6.1. Cell concept 6.1.1. Cell history 6.1.2. Cell theory 6.2. Levels of cellular organization 6.2.1. General characteristics of cells 6.2.2. Prokaryotic cells 6.2.2.1. Prokaryotic cell morphology 6.2.2.2. Structure of prokaryotes 6.2.2.2.1. Bacterial capsule 6.2.2.2.2. Bacterial wall 6.2.2.2.3. Plasma membrane 6.2.2.2.4. Cytoplasm-Ribosomes-Inclusions 6.2.2.2.5. Bacterial DNA 6.2.2.2.6. Bacterial appendages 6.2.2.3. Bacteria Physiology 6.2.3. Eukaryotic cells 6.2.3.1. Animal and plant cell 6.2.3.1.1. Animal eukaryotic cell 6.2.3.1.2. Plant eukaryotic cell 6.2.3.2. Cell Evolution: Endosymbiont Theory 6.3. Size, shape and quantity 6.4. The plasma membrane 6.4.1. Chemical composition of the membrane 6.4.2. The structure of the membrane. The fluid mosaic model 6.4.3. Functions of the plasma membrane 6.4.4. Transport across the membrane 6.4.4.1. Small molecule transport 6.4.4.2. Macromolecule transport 6.4.5. Plasma membrane differentiations 6.5. The cell wall of plant cells 6.5.1. Chemical composition of the cell wall 6.5.2. Cell wall structure 6.5.3. Cell wall differentiations 6.5.4. Cell wall functions 6.6. Extracellular matrix or glucocalyx 6.7. Cytosol or hyaloplasm 6.8. The cytoskeleton 6.8.1. Microfilaments or actin filaments 6.8.2. Intermediate filaments 6.8.3. Microtubules 6.9. Cell membrane and organelle systems 6.9.1. Membrane systems 6.9.1.1. The endoplasmic reticulum 6.9.1.2. Golgi apparatus 6.9.2. Cell organelles 6.9.2.1. Lysosomes 6.9.2.2. Peroxisomes 6.9.2.3. Vacuoles 6.9.2.4. Mitochondria 6.9.2.4.1. Functions of the mitochondria 6.9.2.5. Plastids 6.9.2.5.1. Chloroplasts 6.9.2.6. Ribosomes 6.9.2.7. Centrosome 6.9.2.8. Cilia and flagella 6.10. Cell motility 6.11. The cell nucleus 6.11.1. Characteristics of the cell nucleus 6.11.2. The interphase nucleus 6.11.3. The mitotic nucleus or nucleus in division 6.12. Bibliography 7. Metabolism 7.1. Metabolism 7.1.1. Energetic Aspects of Cellular Chemical Reactions 7.2. Catabolism 7.2.1. Catabolism and obtaining energy 7.2.2. Carbohydrate catabolism 7.2.2.1. Glycolysis 7.2.2.2. Cellular respiration 7.2.2.2.1. Oxidative decarboxylation 7.2.2.2.2. Krebs cycle 7.2.2.2.3. Electron transport chain 7.2.2.2.4. Energy balance of cellular respiration 7.2.2.3. Fermentations 7.2.2.3.1. Alcoholic or ethyl fermentation 7.2.2.3.2. Lactic fermentation 7.2.2.3.3. Other types of fermentations 7.3. Anabolism 7.3.1. Autotrophic anabolism 7.3.2. Photosynthesis 7.3.2.1. Photochemical or light phase 7.3.2.1.1. Photosystems 7.3.2.1.2. Photophosphorylation 7.3.2.1.2.1. Non cyclic photophosphorylation 7.3.2.1.2.2. Cyclic photophosphorylation 7.3.2.2. Biosynthetic or dark phase 7.3.2.3. Factors influencing photosynthesis 7.3.2.4. Products of photosynthesis 7.3.3. Chemosynthesis 7.4. Bibliography 8. Cell reproduction 8.1. The cell cycle 8.1.1. Interphase 8.1.2. Cellular division 8.2. Cellular division 8.2.1. Mitosis 8.2.1.1. Prophase 8.2.1.2. Metaphase 8.2.1.3. Anaphase 8.2.1.4. Telophase 8.2.1.5. Cytokinesis 8.2.1.6. More on mitosis 8.2.2. Meiosis 8.2.2.1. Meiosis I 8.2.2.2. Meiosis II 8.2.3. Meiosis and sexual reproduction 8.2.4. Meiosis and life cycle 8.2.5. Biological importance of meiosis 8.3. Differences and similarities between mitosis and meiosis 8.4. Bibliography 9. Classical genetics 9.1. Genetics basics 9.2. Mendelian genetics 9.2.1. The method 9.2.2. Mendel's Laws 9.2.2.1. Mendel's first law or principle of uniformity in the first generation 9.2.2.2. Mendel's second law or principle of segregation 9.2.2.2.1. Backcross and test crossover 9.2.2.3. Mendel's third law or principle of independent combination 9.3. Gene interaction 9.3.1. Gene interaction between allelic genes 9.3.2. Gene interaction between non-allelic genes that influence for the same trait 9.4. Chromosomal theory of heredity 9.5. Ligation and recombination 9.6. Complex mendelism 9.6.1. Multiple allelism 9.6.1.1. Lethal genes 9.6.2. Pleiotropy 9.6.3. Expressiveness and genetic penetrance 9.7. Sex-linked inheritance 9.7.1. Y-linked inheritance 9.7.2. X-linked inheritance 9.8. Heredity influenced by sex 9.9. Bibliography 10. Molecular genetics 10.1. DNA as hereditary material 10.2. DNA replication 10.2.1. The need for DNA replication 10.2.2. First hypotheses about DNA duplication 10.2.3. Meselson and Stahl experiment 10.2.4. The sense of growth of the new strands 10.2.5. Mechanism of DNA replication 10.2.5.1. Replication in prokaryotes 10.2.5.2. Replication in eukaryotes 10.2.6. Error correction 10.2.7. Enzymes involved in replication 10.3. Gene concept 10.4. "One gene-one enzyme" theory 10.5. Transcription 10.5.1. Mechanism of transcription 10.5.1.1. Transcription in prokaryotes 10.5.1.2. Eukaryotic transcription 10.6. Translation or protein biosynthesis 10.6.1. The genetic code 10.6.2. Mechanism of translation of RNA to proteins 10.6.2.1. Translation in eukaryotes 10.7. Regulation of gene expression 10.8. Bibliography 11. Genetics and evolution 11.1. Mutations 11.2. Types of mutations 11.2.1. Gene or point mutation 11.2.2. Chromosomal or structural mutation 11.2.3. Mutation at the genomic level 11.3. Causes of mutations 11.4. Evolutionary implications of mutations 11.5. Metabolic implications of mutations 11.6. Bibliography 12. Microbiology and biotechnology 12.1. Microbiology 12.2. Viruses 12.2.1. Viral morphology 12.2.2. Viral physiology 12.2.2.1. Lytic cycle 12.2.2.2. Lysogenic cycle 12.2.2.3. Cycles of viruses of special interest 12.2.2.3.1. Flu virus life cycle 12.2.2.3.2. Life cycle of the AIDS virus 12.3. Other acellular forms 12.3.1. Viroids 12.3.2. Prions 12.4. Biotechnology 12.5. Bibliography 13. Immunology 13.1. Infection concept 13.2. Defense mechanisms against infections 13.2.1. Nonspecific mechanisms 13.2.1.1. Primary barriers: external defenses 13.2.1.2. Secondary barriers: internal defenses 13.2.2. Specific mechanisms 13.3. Immunity and immune system 13.3.1. Components of the immune system 13.3.2. Concept and nature of antigens 13.4. The immune response 13.4.1. Humoral immune response: the antibodies 13.4.1.1. Antibody-producing cells: B lymphocytes 13.4.1.2. Antibodies 13.4.1.2.1. Types of antibodies 13.4.1.2.2. Antigen-antibody reaction 13.4.1.3. Immune memory: primary and secondary responses 13.4.2. Cellular immune response: T lymphocytes 13.5. Types of immunity 13.5.1. Natural immunity 13.5.2. Artificial immunity 13.6. Immune system disorders 13.6.1. Autoimmunity 13.6.2. Hypersensitivity 13.6.3. Immunodeficiency 13.6.4. Transplants and the phenomenon of rejections 13.7. Bibliography « Previous \| Next » 3.2.2.1.1. Acylglycerides Acylglycerides (or fats) The acylglycerides or fats or are saponifiable lipids formed by the esterification of one, two or three molecules of fatty acids with a glycerol molecule (propanetriol), releasing one, two or three water molecules. They are also called glycerides or glycerolipids or acylglycerols. Three types are distinguished, according to the number of fatty acids that make up the acylglyceride molecule: Monoacylglycerides: contain a fatty acid molecule. Diacylglycerides: with two fatty acid molecules. Triacylglycerides: with three fatty acid molecules. By Iacopo Leardini. Versión en español de Alejandro Porto. (File:Trigliceridi.gif) [CC0], via Wikimedia Commons Fats, at room temperature, can be: Oils: when the acylglyceride has at least one unsaturated fatty acid, its state is liquid at room temperature. For example, olive oil is an ester of three oleic acids with a glycerin. Tallow: when all the fatty acids are saturated, the acylglyceride is solid at room temperature. For example, beef, horse or goat fat. Butters: when the acylglyceride is semisolid (short chain fatty acids), such as pork fat. In cold-blooded animals and vegetables there are oils, and in warm-blooded animals there are tallow or butters. The acylglycerides are not soluble in water because the groups hydroxyl (-OH) of glycerol, polar , are linked by an *ester linkage* to the groups carboxyl (-COOH) of fatty acids. The triacylglycerols are considered neutral fats because they are nonpolar and insoluble in water. The monoacylglycerides and diacylglycerides have weak polarity by the radicals hydroxyl left free in the glycerin. The triacylglycerols constitute a form of energy storage in animal cells and plant. They can be stored in large quantities in confined spaces without disturbing cellular homeostasis. That is why it is a more effective form of energy reserve than that of carbohydrates. Acylglycerides when they react with bases, produce soap by saponification. The saponification is the formation of soap from saponifiable lipids by chemical reaction between a triacylglycerol and a base (NaOH or KOH). In the reaction, glycerin is released and three molecules of sodium or potassium salts (soaps) corresponding to fatty acids are formed. Animated image: Formation of a triglyceride. Video: What is fat?. The type of fat you eat is more important in your diet than the amount. Functions of acylglycerides Acylglycerides are the main energy reserve in both animals and plants. In plants, they accumulate in vacuoles, and in animals, in adipocytes, specialized cells of adipose tissue. Although starch and glycogen are the main sources of energy due to their rapid mobilization as they are soluble in water, fats provide much more energy (9 Kcal / g). Acylglycerides also act as thermal insulators. For example, by forming a layer of fat under the skin of some homeothermic animals that live in cold climates to be able to live with low temperatures. Other hibernators accumulate fat under the skin and around organs to use as food during the hibernation period. They are good mechanical shock absorbers. They absorb the energy of blows and, therefore, protect sensitive structures or structures that suffer continuous friction. Fundamental ideas about fats or acylglycerides The triglycerides, fats or triacylglycerols, are formed by the esterification of one molecule of glycerol with three molecules of fatty acids, which may be identical or different. The triacylglyceride is formed by the union of the carboxyl groups (–COOH) of three fatty acids with the three hydroxyl groups (-OH) of a glycerol molecule, forming three ester bonds and the release of three water molecules Depending on how these fatty acids are, triacylglycerides can be: Saturated fats, when the fatty acids are saturated, without presenting double bonds between the carbons of the hydrocarbon chain. Monounsaturated fats, when the fatty acids are monounsaturated, containing a double bond. Polyunsaturated fats, when the fatty acids are polyunsaturated, containing several double bonds. The main function of triacylglycerides is that of energy reserve, in animals and plants. They also act as thermal insulators, as a food store and as mechanical protection for certain organs, such as the heart and kidneys. Triacylglyceride can be saponified when subjected to alkaline hydrolysis with NaOH and KOH solutions, producing soap, a sodium or potassium salt (stearate), and glycerin, which is an alcohol. Have you ever asked in college entrance exams for the difference in triglycerides and phosphoglycerides or phospholipids: Triglycerides: formed by the union of glycerin and three fatty acids. Phosphoglycerides or phospholipids: formed by the union of glycerin, two fatty acids, phosphoric acid and an amino alcohol (serine). Licensed under the Creative Commons Attribution Share Alike License 4.0 « Previous \| Next » These pages are semi-automatically translated from the web Biology 2nd Baccalaureate. Biología de 2º de Bachillerato (biologia-geologia.com). You can make any suggestion, question, comment, ..., in our forum 2º Bachillerato Biología - Foro de biologia-geologia.com
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Acylglycerides (or fats)

Functions of acylglycerides