Search results for: 'dust particles'

Watch Later 1:29

By: HWC, Views: 5989

Louis Pasteur designed a procedure to test whether sterile nutrient broth could spontaneously generate microbial life. To do this, he set up two experiments. In both, Pasteur added nutrient broth to flasks, bent the necks of the flasks into S shapes, and then boiled the broth to kill any existing...

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Dietary Cholesterol & LDL

By: HWC, Views: 6013

LDL comprises 60–70% of total blood lipoproteins and is responsible for carrying cholesterol particles throughout your body. Having a lot of cholesterol carried by LDL lipoproteins is associated with an increased risk of heart disease. In fact, the higher the level, the greater the risk. ...

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Hershey Chase Experiments

By: HWC, Views: 3787

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Watch Later 2:44

Introduction to Human Immunodeficiency Virus (HIV)

By: Administrator, Views: 9548

Human immunodeficiency virus gains entry into helper T cells, uses the cell DNA to replicate, interferes with normal function of the T cells, and destroys the normal cells. 1 in 10 persons with AIDS: age 50 or older. 4% of all AIDS cases: age 65 or older. AIDS’ main form of treatment: an...

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Transcription - Introns and exons

By: HWC, Views: 3738

In most eukaryotic genes, coding regions (exons) are interrupted by noncoding regions (introns). Exon - RNA sequences in the primary transcript that are found in the mRNA. Intron - RNA sequences between exons that are removed by splicing. During transcription, the entire gene is copied ...

Watch Later 5:36

How does asthma work?And How do you treat asthma?

By: HWC, Views: 5574

These are the parts of the respiratory system. Sinuses and Nasal Passages Mouth Windpipe (Trachea) Lungs Airways (Bronchial Tubes) Airsacs (Alveoli) When we breathe, air moves easily in and out of the lungs. The small airways are also called bronchial tubes. The side of the tube is...

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HIV replication/ Replication cycle of HIV

By: HWC, Views: 3779

Replication cycle of HIV, one of the retroviruses. The HIV virus is surrounded by a lipid envelope with embedded proteins. A coat of viral proteins surrounds two strands of RNA and the enzymes used during replication. The virus attaches to and enters the host cell. Viral reverse trans...

Watch Later 1:40

Digestive chemicals - types & enzymes

By: HWC, Views: 6600

• Chemical digestion breaks down food as it moves through the digestive tract. • Using enzymes and other digestive chemicals, the process reduces food particles into nutrient molecules that can be absorbed. • Most chemical digestion is done by the actions of digestive enzymes. • O...

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How proteins function? How do proteins work?

By: HWC, Views: 6251

How proteins function is really about how proteins "do work" in cells. How do proteins work? Let's start thinking about protein function by looking at something important to you: your hair. Keratin is a structural protein that is composed of 2 intertwined or helical strands. Keratin is also f...

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