Antioxidants and Oxidative Stress in Exercise
Sources of Oxidative Stress
- Uncoupling of the electron transport chain: 2-5% of the total electron flux escapes the respiratory chain to make O2-. Exercise increases ATP demand. O2 uptake can increase 20-fold. O2 flux through active muscle may increase 100-fold. So there is an increased possibility.
- Ischemia-reperfusion: Intense exercise can lead to tissue hypoxia. Hypoxia promotes an excess of electron donors, NADH. Xanthine oxidase. After a period of ischemia, an increased neutrophil infiltration
Human Digestion: Enzymes, Absorption, and Assimilation
Why is Digestion of Large Food Molecules Essential?
Firstly, the food we eat is made up of many compounds produced by other organisms. Not all of these are suitable for human tissues. Therefore, these compounds have to be broken down and reassembled so that our bodies can use them. Secondly, food molecules must be small enough to be absorbed by the villi in the intestine through diffusion, facilitated diffusion, or active transport. Consequently, large food molecules need to be broken down into smaller
Read MoreBiotechnology and Genetic Engineering: Applications and Impact
Biotechnology and Genetic Engineering: Applications and Impact
Biotechnology is the use of biological processes to obtain goods and services from living organisms. The oldest examples are fermentations, such as the production of alcohol in wine, lactic acid in milk, or acetic acid in vinegar.
Genetic Engineering: A Powerful Tool
Genetic engineering is a technology for obtaining goods and services that emerged following the discovery of DNA. Its applications are significant, including the synthesis
Read MoreCell Membrane Structure: Lipids, Proteins, and Fluidity
Cell Membrane Structure
The plasma membrane, a thin layer of lipids and proteins, separates a cell from its surrounding. To maintain their internal environment, the cells of all organisms must constantly exchange molecules and ions with the fluid environment that surrounds them. Transport proteins move particular ions and molecules, including water, in a directed way across the membrane.
Lipids in Biological Membranes
Biological membranes consist of lipids. Phospholipids and sterols (such as cholesterol)
Read MoreMicroalgae: Characteristics, Cultivation, and Applications
Microalga, in its narrowest sense, is a photoautotrophic, unicellular eukaryote which uses CO2 and gains energy from light.
In eukaryotic algae, the donor DNA is integrated into the genomic or chloroplast DNA. Only Chlamydomonas reinhardtii (single-cell green alga with 2 flagella) has a history of stable genetic modifications and subsequent cultivation of the GM-strains. Vegetative cells of C. reinhardtii are haploid. Under stress conditions, e.g., nitrogen starvation, haploid gametes develop. There
Read MoreHuman Genome and Genetic Engineering: Advances and Implications
The Human Genome
The human genome is the complete set of genes within a human being. It contains all the information necessary for basic human development. In the human species, the genome is packaged into 46 chromosomes: 23 from the father and 23 from the mother. These 46 chromosomes are grouped in pairs. 22 pairs are autosomes, which do not carry information about sex characteristics, and one pair are sex chromosomes. Females have two identical X chromosomes (XX), while males have one X and one
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