Protein Structures and Functions: From Amino Acids to Enzymes
Proteins: Structures and Functions
Proteins are organic biomolecules formed by carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), often containing sulfur (S), iron (Fe), zinc (Zn), and copper (Cu). They account for 50% of the dry matter of a living being. Their molecular weight is quite high despite being composed of core building blocks (monomers) of low molecular mass. The monomer of proteins is called an alpha-amino acid. Proteins have a variety of functions to perform, and they are found
Read MorePhotosynthesis and Cellular Metabolism: An In-Depth Look
Anabolism
The path is constructive metabolism, the synthesis pathway from simple molecules to complex molecules. There are two stages:
- Heterotrophic Anabolism: Simple organic molecules to complex organic molecules such as starch, fat, or proteins. Its objective is the synthesis of macromolecules (energy reserves).
- Autotrophic Anabolism: The passage of inorganic molecules (H2O, CO2, NO3–) to simple molecules such as glucose or glycerin. These are beings that make their organized matter from inorganic
Squid: Anatomy, Behavior, and Classification
Squid: Anatomy and Behavior
Squid have two gills, and a circulatory system that consists of a systemic heart and two branchial hearts. Their tentacles are equipped with highly muscular suckers, and if lost, they cannot grow back. Squids can blend in with their surroundings with ease to avoid predators.
They also have cells called chromatophores in their skin that give squids the ability to change color if they feel threatened, a strategy that is combined with the expulsion of the ink they produce.
Read MoreCellular Respiration, Nutrition, and Human Body Systems
Cellular Respiration and Energy Production
Nutrients contribute to the fuel for cell energy. Cells use this energy to perform their functions. Cellular respiration occurs in the mitochondria. Glucose is the nutrient most commonly used. There are three phenomena in this process:
- Consumption of oxygen, whose presence is necessary for combustion
- Release of energy, used by cells
- Production of carbon dioxide and water
The useful energy contained in nutrients are chemical substances. This energy is called
Read MoreBiological Processes: From Cells to Organisms
Goiter and Diabetes
Goiter: Pathological inflammation of the thyroid gland. Diabetes: Disorder in the production of the quantity of insulin needed.
Tropism in Plants
Tropism: Growth responses with which plants react to different external stimuli. Phototropism: Growth toward the light or in the opposite direction. Photojournalism: Variable duration of daylight and darkness in the year. Blooming: Process affected by the photoperiod. Geotropism: The plant’s response to gravity. Thigmotropism: The plant’
Read MorePlant Reactions, Hormones, Movements, and Seed Development
Item 12: The Function of Relation
The function of relation consists of the capacity that living things have to capture internal and external stimuli and prepare responses that ensure their survival. The reaction usually occurs with a movement or by secreting hormones. Plants detect stimuli because they have specialized cells that function as receptors, and these receptors are found in the epidermis of organs.
Types of Receptors
There are different types of receptors depending on the stimulus:
- Photoreceptors