Circulatory System: Heart, Blood, Vessels, and Function
Circulatory System: Composition and Function
The circulatory system consists of the heart and blood vessels. Blood is composed of 45% blood cells and 55% plasma, which is a liquid.
Blood Plasma
Blood plasma is a yellowish liquid consisting of water and a great variety of dissolved substances.
Blood Cells
Blood cells are formed in the red bone marrow. There are three types:
- Red blood cells: The most abundant cells in the blood.
- White blood cells: Several types of white blood cells exist, and all have a
Protein Synthesis, Cell Division, and Homeostasis
Protein Synthesis
Describe protein synthesis, detailing how so many things can be generated from so few (i.e., 4 organic bases, 20 amino acids, protein formation).
Protein structure:
- 1º Primary: Linear sequence of amino acids
- 2º Secondary: Twisting of the polypeptide chain (e.g., alpha-helices and beta-sheets)
- 3º Tertiary: Three-dimensional folding of the polypeptide chain
- Quaternary: Arrangement of multiple polypeptide chains into a functional protein complex
Cell Division: Mitosis and Meiosis
Detail
Read MoreNutrition and Digestion: A Comprehensive Look
Nutrition and Substance Exchange
Nutrition involves the exchange of matter and energy between organisms and their surrounding environment. To perform this exchange, different tracts and systems work together to obtain nutrients and oxygen, which are distributed to each cell of the body. They also expel waste substances out of the body.
Substance Exchange in Unicellular Organisms
Unicellular organisms exchange substances directly with their surrounding environment through a plasma membrane.
Substance
Read MoreUnderstanding Genetic Mutations: Types, Causes, and Evolution
Understanding Genetic Mutations
Mutations: Random alterations of genetic material, usually involving deficiencies, can be lethal. They are usually recessive and remain hidden, contributing to population variability.
Somatic Mutations
Unless they become cancer cells, somatic mutations are often irrelevant because non-viable cells can be replaced. When cells divide by mitosis, they give rise to a colony or clone of mutant cells resembling the former.
Germline Mutations
Germline mutations are transcendental,
Read MoreEndoplasmic Reticulum: Protein Synthesis, Lipid Metabolism, and Detoxification
Endoplasmic Reticulum Functions
Protein Synthesis (Rough ER)
The rough endoplasmic reticulum (RER) is crucial for the synthesis of proteins destined for export from the cell or for delivery to other intracellular locations. This process begins with free ribosomes in the hyaloplasm. The key difference between mRNA for exportable proteins and non-exportable proteins lies in the signal hypothesis.
The mRNA of exportable proteins contains a series of signal codons immediately after the start codon (AUG)
Read MorePlant and Animal Kingdom: Characteristics and Anatomy
Plant Groups and Their Characteristics
Bryophytes: Nonvascular plants (mosses, liverworts, hornworts)
- Lack true roots and vascular tissues
- Small size, restricted to moist environments
Seedless Vascular/Monilophyta: Ferns, horsetails
- Have vascular tissues but lack seeds
- Reproduce via spores
- Larger size and more complex structures than bryophytes
Gymnosperms: Seed plants with naked seeds (conifers, cycads, ginkgos)
- Produce seeds in cones
- Most have woody stems
Angiosperms: Flowering plants
- Produce flowers and