Week 5 P2

What are antibodies?

Proteins that chemically defend against foreign substances.

What cells produce antibodies?

B lymphocytes.

When are antibodies produced?

When other lymphocytes (T lymphocytes) detect the presence of foreign bodies.

What are antigens?

Foreign substances recognized by the immune system.

What is the primary function of carbohydrates?

Provide short-term energy for cell metabolism.

What is another name for carbohydrates?

Saccharides.

What percentage of cell content is carbohydrates?

1%.

Where are carbohydrates most abundant?

Liver and muscle tissue.

What do carbs aid in structural support?

Are important structural parts of cell walls and intercellular materials.

What elements make up carbohydrates?

Carbon, hydrogen, and oxygen.

What are lipids?

Fats or fatlike substances that are organic macromolecules.

What percentage of cell content is lipids?

2%.

What are lipids composed of?

A molecule of glycerin and three fatty acids.

What are two major functions of lipids?

Cell membrane structure and thermal insulation.

What are the two types of nucleic acids?

DNA and RNA. Very large, complex macromolecules.

What are nucleic acids main function?

The control molecules for cell function.

Where are nucleic acids located?

In the nucleus.

What percentage of cell content is nucleic acids?

1%.

What is the most radiation-sensitive target molecule?

DNA.

What is the main function of DNA?

Store genetic information and direct cell activities.

What is the shape of DNA?

Double helix, composed of two long sugar phosphate chains.

What forms the two outer chains of DNA?

Sugar and phosphate.

What connects DNA base pairs?

Hydrogen bonds.

What are the four nitrogenous bases in DNA?

Adenine, thymine, guanine, and cytosine.

What does adenine pair with?

Thymine.

What does cytosine pair with?

Guanine.

What determines the genetic code?

The sequence of nitrogenous base pairs.

What are chromosomes composed of?

DNA and proteins.

How many chromosomes are in a human somatic cell?

46 chromosomes.

How many chromosome pairs are in somatic cells?

23 pairs.

How many chromosomes are in reproductive (germ) cells?

23 chromosomes.

What are genes?

Segments of DNA that serve as units of heredity.

What do genes control?

Protein formation, cytoplasmic activity, and hereditary characteristics.

What are the two types of RNA emphasized in the lecture?

mRNA and tRNA.

What does mRNA stand for?

Messenger RNA.

What does tRNA stand for?

Transfer RNA.

How does RNA differ structurally from DNA?

RNA is single-stranded helix.

Where is Most RNA found?

The nucleolus attached to the endoplasmic reticulum.

What sugar does RNA contain?

Ribose.

What base replaces thymine in RNA?

Uracil.

What is the function of mRNA?

Carry genetic instructions from DNA to ribosomes.

What is the function of tRNA?

Receives genetic code from mRNA and brings amino acids to ribosomes.

Where does protein synthesis occur?

Ribosomes.

What determines which proteins a cell produces?

DNA.

What happens when radiation interferes with protein synthesis?

Cell damage may occur.

What is cytoplasm?

The material making up the bulk of the cell that contains all molecular components except DNA.

What is the main component of the nucleus?

DNA.

What is the function of the endoplasmic reticulum?

Channel that allows the nucleus to communicate with the cytoplasm.

What is the function of mitochondria?

Produce energy.

What are mitochondria commonly called?

The powerhouse of the cell.

What is the function of ribosomes?

Protein synthesis.

What is the function of lysosomes?

Digest cellular fragments using enzymes.

What is the function of water outside the cell?

Transport, temperature regulation, lubrication, and protection.