Nutrients, Digestion, and Your Body
Core Concepts in Nutrition and Digestion
Key Definitions
- Feeding: The ingestion of food selected from the environment, making up our diet.
- Food: Any substance (solid or liquid) usually ingested for living, nutritional, and psychological purposes.
- Nutrition: An involuntary process by which our body extracts the nutrients our cells need from food and transforms them into its own structures.
- Nutrients: Food substances that provide matter and energy for our cells to perform vital functions.
- Basal Metabolism:
Bacteriophage Biology: Structure, Life Cycles, and Replication
Phage Structure and Components
Most bacteriophages (phages) possess a distinct structure. Tailed phages, comprising about 95% of known phages, have double-stranded DNA (dsDNA) enclosed within a protein capsid shell. The majority feature a tail, which can be:
- Long and flexible
- Long and contractile
- Short
An adsorption apparatus, including tail fibers and tail spikes, facilitates attachment to host cells.
Measuring Phage Infections: The One-Step Growth Curve
Viral infections, including those by phages, can
Read MoreUnderstanding Assisted and Artificial Reproduction Techniques
Assisted and Artificial Reproduction Techniques
Assisted reproduction, also known as artificial reproduction, involves the insertion of sperm into a woman’s uterus, timed to coincide with ovulation.
In Vitro Fertilization (IVF)
In in vitro fertilization (IVF), eggs are removed from the woman after hormone treatment to stimulate the ovaries. The eggs are then fertilized by sperm. When the sperm count is low, a single sperm can be injected directly into the oocyte using intracytoplasmic sperm injection
Read MorePhotosynthesis: Light Energy to Chemical Transformation
Photosynthesis: Transforming Light into Chemical Energy
Photosynthesis, occurring within chloroplasts, is the transformation of light energy into chemical energy. This energy is used to produce organic matter from inorganic substances. It’s essentially the reverse of respiration and is a constructive process.
Solar energy is absorbed by photosynthetic pigments in chloroplasts and used for the synthesis of ATP and glucose from CO2 and H2O. In mitochondria, the released energy is stored in the form
Somatic vs Germ Cells: Understanding Cell Division
Somatic Cells and Germ Cells
Somatic cells: These cells make up the body tissues of a living organism. They divide by mitosis and always have two sets of chromosomes or genetic material (2n), making them diploid.
Germ cells: These cells merge with another cell to form a new sexual being. They divide by meiosis and only have one set of chromosomes (n), making them haploid cells.
Haploid and Diploid Cells
Number of chromosomes:
- Haploid: Contains half the normal number of chromosomes (23).
- Diploid: Contains
Blood Composition, Functions, and Vessels: A Detailed Look
Blood: Composition and Functions
Blood is a viscous, salty-tasting liquid that circulates within the circulatory system. The average human body contains approximately 5.5 liters of blood.
Key Features of Blood
- Carries nutrients and oxygen to all cells.
- Collects waste products from cell metabolism.
- Plays a crucial role in defending the body against infection.
- Transports hormones, which are essential for controlling bodily functions.
- Participates in regulating body temperature by distributing heat from warmer