Table of Contents
What are Eenzymes?
Enzymes (or enzymes) are proteins that act like biological catalysts (biocatalysts). Catalysts speed up chemical reactions. Substrates are molecules on which enzymes can act. The enzyme then converts these substrates into other molecules called products. Enzyme catalysis is required for almost all metabolic processes within the cell to occur at sufficient rates to sustain life. 8.1 Metabolic pathways are dependent on enzymes to catalyze individual processes. Enzymology is the study of enzymes. The pseudoenzyme analysis field recognizes that some enzymes lost their ability to catalyze biological reactions during evolution. This is often evident in their amino acid sequences or unusual ‘pseudocatalytical’ properties.
More than 5,000 types of biochemical reactions can be catalyzed by enzymes. The unique three-dimensional structure of enzymes is what gives them their specificity.
Enzymes, like all catalysts can increase the reaction speed by lowering their activation energy. Many enzymes make the conversion of substrate into product much faster than others. Orotidine 5’phosphate decarboxylase is an extreme example. This enzyme allows a reaction that normally takes millions of years to happen in just a few milliseconds. Enzymes are chemically similar to any catalyst. They are not consumed in chemical reaction nor alter the equilibrium of a react. Because enzymes are more specific than other catalysts, they differ from others in that they can be used to alter the equilibrium of chemical reactions. Other molecules can affect enzyme activity. Inhibitors are molecules that reduce enzyme activity and activators are molecules which increase enzyme activity. Enzyme inhibitors can be found in many therapeutic drugs as well as poisons. Excessive heat can cause enzyme activity to decrease markedly, and enzymes may lose their structure and catalytic capabilities.
Commercially, some enzymes are used in the production of antibiotics. To speed up chemical reactions, some household products contain enzymes. For example, enzymes in biological washing powders can break down protein, starch, or fat stains, while enzymes in meat tenderizers can break down proteins into smaller molecules that make it easier to chew.
What is a Hormone?
A hormone is any member a group of signaling molecules found in multicellular organisms. They are transported through intricate biological processes to distant organs to control physiology, behavior, and physiology. Hormones are essential for proper development of plants, animals, and fungi. A hormone can be described as a signalling molecule acting far from the site of its production, but this definition is too loose. Eicosanoids, e.g. Prostaglandins, thromboxanes, and steroids (e.g. oestrogen, brassinosteroid, amino acid derivatives (e.g. autin and epinephrine), amino acid derivatives (e.g. Insulin and CLE peptides), and gases (e.g ethylene or nitrous oxide).
Hormones allow for communication between tissues and organs. Hormones regulate many physiological and behavioral processes in vertebrates. They are responsible for the regulation and control of growth, development, movement and reproduction as well as mood manipulation. Hormones control almost every aspect of plant development, from germination through senescence.
Hormones can affect distant cells by binding specific receptor proteins in the target cells, leading to a change of cell function. A hormone binding to a receptor activates a signal transduction pathway, which typically activates gene transcription. This results in an increase in target protein expression. There are also non-genomic ways hormones can interact with genomic effects. Second messengers are used to deliver water-soluble hormones, such as peptides or amines, to the target cells’ surface. Lipid-soluble hormones (such as steroids), generally pass through target cells’ plasma membranes (cytoplasmic or nuclear) to reach their nuclei. Brassinosteroids, which are lipid-soluble but still bind to the receptor on the cell surface, are a notable exception.
Endocrine glands in vertebrates are specialized organs that secrete hormones to the endocrine system. Hormone secretion is regulated by negative feedback and responds to biochemical signals. High blood sugar (serum glucose content) encourages insulin synthesis. Insulin is then activated to lower glucose levels and maintain homeostasis. This results in decreased insulin levels. Water-soluble hormones can be easily transported through the circulatory systems after they are secreted. To form ligand protein complexes, lipid-soluble hormones must attach to carrier plasma glycoproteins (e.g. thyroxine binding globulin (TBG). Although fully active hormones may be released into bloodstreams (as in insulin and growthhormones), some hormones travel as prohormones. These must be activated in certain cells using a series activation steps that are often highly controlled. The hormones are secreted by the endocrine system directly, usually via fenestrated blood vessels, while the exocrine system indirectly uses ducts. Paracrine hormones diffuse through interstitial spaces to target tissue.
Although plants lack special organs to secrete hormones, there is spacial distribution. The shoot apical meridtem is where the hormone auxin is found, and the tips of young leaves are the main sites for production. Because there are no specialised glands, the location of hormone production may change over time. The plant’s environment and age will also affect the site of hormone production.
Difference between enzymes and hormones – enzymes vs hormones
|Enzymes are biological macromolecules that speed up biochemical reactions, without any changes.
|Hormones can be molecules such as a peptide or steroid (eg. estrogen), that are produced in one area of an organism. They trigger specific cellular reactions within target tissues and organs further away.
|Also known as
|All enzymes, except for ribozymes ( RNA) with catalytic activities, are proteins.
|There are many types of hormones: terpenoids and steroids, terpenoids and amines.
|Vitamins and inorganic elements are the prosthetic groups of enzymes, which means that they can’t act without them.
|These prosthetics are not available to them.
|These macromolecules have a higher molecular weight.
|They are comparatively light in molecular weight.
|Site of action
|Enzymes are most commonly found at their source, i.e. In the cells they are made.
|The site of origin may be a distance from where hormones are active.
|They can either be carried to another location by ducts or act intracellularly.
|Usually carried by blood to the target organ.
|The reaction ends
|They are involved in biological reactions and their chemical composition can be changed.
|They can be reused.
|They can’t be reutilized in this way.
|Enzymes are substrate-specific, i.e. It all depends on the substrate that the enzyme is to be used.
|Hormones have a target cell-specific nature and are dependent on positive and negative feedback mechanisms.
|Exocrine glands secrete enzymes in animals.
|Endocrine glands synthesize hormones and secrete them.
|The secretory glands of the stomach, pancreas, and salivary glands.
|Glands include Pituitary and Pineal, Thymus. Adrenal, Thyroid, Pancreas.
|Cell Membrane and Diffusibility
|They cannot be absorbed through cells membranes.
|They can be diffused through cell membranes.
|It is not possible for enzymes to be translocated from one cell part to the next.
|Polar translocation is a common feature of most hormones.
|Type of reaction
|They can cause reversible reactions.
|Hormone-controlled reactions cannot be reversed.
|Time to react
|They are quick to act.
|Some hormones have a rapid action, while others are slower acting and have a longer lag time.
|It speeds up metabolic physiological processes.
|They can be excitatory, or inhibitory in their actions.
|Increase in conception
|The reaction rate increases as the concentration of the substances is increased to a certain point.
|Metabolic disorders and diseases can be caused by hormone deficiency or overproduction.
|They can be used as catalysts to increase the rate of biochemical reactions.
|Signal passers are those who move from one cell to another or between different organs.
|Participation in bodily functions
|Participate in many metabolic reactions, such as digestion.
|They play a role in the regulation of energy, heat, and internal balance of water and ions.
|After receiving messages from hormones, enzymes are at work.
|They communicate message and don’t rely on enzymes for function.
|Stimulation results in the production of these substances.
|As a stimulant
|Function dependent on
|They function on positive and/or negative feedback mechanisms.
|Tissues or cells
|Enzymes act as biological catalysts. They are catalysts for biological reactions.
|Hormones do not act as a catalyst. They are merely catalysts for biochemical reactions.
|Role in metabolism
|They do not participate in metabolic functions, but rather are used to support metabolism.
|They are used in metabolic functions.
|They can’t regulate morphogenesis.
|Regulating morphogenesis, particularly secondary sex characters.
|They work under very strict temperature and pH conditions.
|They can be controlled by brain and external factors, but not by temperature or pH.
|There are specific inhibitor molecules that can control the enzyme reaction rate.
|Special inhibitor hormones can be used to control hormones.
|Contribution to life
|They serve a limited, but important function.
|They serve many functions, including controlling body growth, reproduction, and physiology.
|Variation in age
|They remain the same throughout life and don’t change with age.
|They change as we age. Some hormones become more prominent as we age, while others disappear with age.
|They are more common than others and most of their diseases are due to insufficiency.
|Many disorders can be caused by hormonal changes. This can be caused by excess or insufficiency.
|Hydrolases, isomerase, and oxidases
|Examples of hormones include oxytocin (cortisol), testosterone, estrogen, and estrogen in animals. Abscisic acid and cytokines are examples.