Understanding Iron Metabolism, Hemostasis, and Blood Clotting
Iron Metabolism (Fe)
Iron is constantly lost through urine, approximately 1 mg/day. Iron consumption can be in ferrous or ferric form. Only about 10% of consumed iron is absorbed, necessitating a daily intake of 10 mg. This minimum iron intake should be doubled or tripled during pregnancy or menstruation.
Total iron reserves in the body are between 4-5 grams. 70-75% of this iron is in the form of hemoglobin, 15-20% as transferrin, 5% as myoglobin, and 1% in various other forms.
Iron is consumed in
Read MoreCellular Transport, Metabolism, Photosynthesis & Respiration
Cellular Energy and Material Exchange Processes
Cellular Transport
Cellular transport refers to the exchange of substances between the cell interior and the exterior environment through the plasma membrane, or the movement of molecules within the cell.
Metabolism: Catabolism and Anabolism
Catabolism
Catabolism is the part of metabolism involving the transformation of complex biomolecules into simpler molecules. This process releases chemical energy, which is stored in the phosphate bonds of ATP molecules.
Read MoreProkaryotic and Eukaryotic Cells: Structure, Function, and Medical Significance
Prokaryotic and Eukaryotic Cells
Endospore Formation
- Spores formed many millions of years ago (mya) are still viable.
- Looking for these is what that phase contrast microscope was for.
Endospore Formation
- Stimuli for sporulation
- Depletion of nutrients
- Chemical signals
- Are there a lot of me around?
- Only a subset sporulate → rest wait it out (or try)
- Vegetative cell → sporangium
- Sporangium → endospore
- Hardiest of all life forms
- Withstand extremes in:
- heat, drying, freezing, radiation, and chemicals
- Regulated
- Withstand extremes in:
Human Sexual Reproduction: Stages, Fertilization, and Development
Human Sexual Reproduction
In sexual reproduction, two cells unite (sperm and egg), each from one individual of the opposite sex, to form a zygote. The zygote develops and produces an offspring that is genetically different from the parents.
Puberty and Adolescence
Puberty: The acquisition of sexual maturity during adolescence.
- Primary Sexual Characteristics: Reproductive organs.
- Secondary Sexual Characteristics: Hair, voice changes, etc.
Adolescence: The stage from approximately 9 to 18 years of age,
Read MoreUnderstanding the Human Digestive System: Organs, Glands, and Processes
The Human Digestive System: An Overview
The digestive system is a complex network of organs working together to break down food and absorb nutrients. It consists of the following:
- Mouth: Where digestion begins with saliva.
- Pharynx: The throat, a passageway for food and air.
- Esophagus: A muscular tube that carries food to the stomach.
- Stomach: An organ that churns food and mixes it with gastric juices.
- Small Intestine: The primary site for nutrient absorption.
- Large Intestine: Absorbs water and forms stool.
Cardiac Pacemakers: How They Work and Save Lives
The Cardiac Pacemaker
Normally, the heart carries out its job of pumping blood by means of a built-in system of rhythmic electrical impulses. These impulses are carried through the heart by nerves that lead to its muscle fibers, causing them to contract. Two main nerves lead to the ventricles, which are responsible for pumping blood. If one of these nerves fails to function properly, the heart beats irregularly. If both nerves fail for a few seconds, the brain receives insufficient blood, and the
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