Protein Structure and Properties: A Comprehensive Look
Primary Structure of Proteins
The primary structure is the most basic form of protein organization. It is determined by the amino acid sequence of the protein chain, i.e., the number of amino acids and the order in which they are linked by peptide bonds. The amino acid side chains extend from a main chain. By convention, the order of writing is always from the amino-terminal to the carboxy-terminus. A characteristic zigzag in their disposal is due to the planarity of the peptide bond rotation that
Read MoreHuman Nervous, Endocrine, and Reproductive Systems
The Human Nervous System
The nervous system in humans is, from a human point of view, the most perfect machine known. It consists of a central nervous system and a peripheral nervous system. The central nervous system consists of the brain and spinal cord.
Brain Development
The brain consists of three initial vesicles: the forebrain, midbrain, and hindbrain. Later, in embryological development, five vesicles originate by subdivision:
- The forebrain gives rise to the telencephalon and diencephalon.
- The
Animal and Plant Nutrition: Processes and Adaptations
Nutrition
Nutrition describes the processes by which living things take in external substances and turn them into matter and energy.
Autotrophs
Autotrophs produce their own organic matter from inorganic substances taken from the environment. They can be:
- Photosynthetic: Obtain energy from sunlight.
- Chemosynthetic: Obtain energy from chemical reactions.
Heterotrophs
Heterotrophs feed on other organisms or their remains. They can be carnivores, herbivores, omnivores, filter feeders, scavengers, etc.
Processes
Read MoreEnzyme Reactions and DNA/RNA Structure: A Detailed Analysis
Enzyme Reactions: Key Processes in Metabolism
Enzyme reactions are chemical conjugates in metabolism, involving very low concentrations and accelerating reactions involved with decreasing activation energy. They are water-soluble globular proteins that are well in the diffusion of organic liquids. They can act at intracellular and extracellular levels (where they are secreted).
Chemical Nature
Enzymes can be shaped by one or more polypeptide chains, denominated solely as protein enzymes, or a part
Read MoreEvidence and Mechanisms of Biological Evolution
Evidence of Evolution
Biological evolution is possibly the most important process that affects all living creatures on Earth. This process does not shine directly on certain living beings, since it is a process that lasts a long time and takes thousands or millions of years to manifest. Nevertheless, it is an unstoppable process that began with the appearance of life and, since then, has lost none of its vigor. We can be more certain of the existence of this process in the past because, as we just
Read MorePlant Reproduction: Asexual and Sexual Methods
Plant Reproduction: Asexual and Sexual Methods
The Diplohaplontic Cycle
The diplohaplontic cycle is the cycle that characterizes plants with alternating generations: a diploid sporophyte and a haploid gametophyte.
The sporophyte undergoes meiosis to form haploid spores. These spores germinate and give rise to haploid gametophytes, which produce gametes by mitosis. The gametes fuse, forming a diploid zygote that divides to form a diploid sporophyte.
Types of Reproduction in Plants
Plants have two basic
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