Molecular Biology: RNA, DNA, and Embryonic Development
- Types of RNA:
- Messenger RNA (mRNA) is the type of RNA that carries information from DNA to ribosomes.
- Transfer RNA (tRNA) and ribosomal RNA (rRNA) are key elements in the translation process, and various types of RNA regulators.
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- Operon model: The model of prokaryotic gene regulation: the operon model was proposed in 1961 by Francois Jacob and Jacques Monod. The phenomenon that inspired the idea was enzyme induction. Groups of genes that encode related proteins are grouped into units known as operons.
Vitamins: Functions, Sources, Deficiencies, and Toxicity
Vitamin A
Vitamin A is a group of compounds organized into two classes:
- Retinoids: Preformed vitamin A found in food of animal origin, such as meat, eggs, and dairy products.
- Carotenoids: Precursors of vitamin A present in plant foods (fruits and vegetables), like beta-carotene from green leaves.
Features
- Cell differentiation
- Reproduction
- Growth
- Development of bones and teeth
- Synthesis and maintenance of a healthy epithelium (like the retina)
- Immune system integrity
- Prevention of night blindness (an essential
Essential Functions and Structures of Cells and Tissues
Essential Functions of Cells
Nutrition Function
Type:
- Autotroph bodies: Taken from the exterior with simple inorganic molecules that build organic molecules they need.
- Heterotrophic organisms: Are unable to synthesize organic molecules and have to obtain them from other agencies. They depend on the material synthesized by autotroph-based organizations.
Cellular metabolism: The nutrients undergo a series of complex chemical reactions. These chain reactions are called metabolic pathways, and all the metabolic
Read MoreFungi, Viruses, Bacteria, Archaea, and Protists: Key Characteristics
Fungi: Key Characteristics
What distinguishes the fungi from other kingdoms? Fungi are eukaryotic organisms, meaning their cells have a nucleus and other organelles enclosed within membranes. Unlike plants, fungi do not perform photosynthesis. They obtain nutrients through absorption, secreting enzymes to break down complex organic matter into simpler compounds. Their cell walls contain chitin, unlike the cellulose found in plant cell walls.
What are the key physical characteristics of fungi? Fungi
Read MoreHuman Physiology: Essential Mechanisms and Functions
Blood Glucose Regulation
Rising blood glucose – Detected by insulin-secreting cells in the pancreas. The pancreas secretes insulin, causing body and liver cells to take up glucose and store it as glycogen. Glucose levels decline, and insulin release stops. Return to homeostatic blood glucose level.
Specialization of Cardiac Muscle Cells
Describe the specialization of cardiac muscle cells and how they support the electrical and mechanical functions of the heart:
- Intercalated Discs: Specialized connections
Animal Kingdom: Invertebrates and Vertebrates
Invertebrates
- Animals without an internal skeleton, although they may have an external skeleton or exoskeleton.
- Some groups with radial symmetry; we cannot draw a single axis that divides the animal into two symmetrical parts. Other groups with bilateral symmetry.
- Distinctive features for each sub-group (phylum).
Vertebrates
- Animals with an internal skeleton, or endoskeleton. It may be bone or cartilage.
- Animals with bilateral symmetry; that is, their body may be divided by an imaginary axis into two