Past bio exams q&a

a cell has a diameter of 100 micrometers, what is that length in millimeters?

0.1 mm

What is the OH- concentration of a solution with an H+ concentration of 1x10^-6?

1x10^-8

How many bonds does nitrogen usually form in biological molecules?

3

The atomic weight if water is 18. In 100 grams of water, how many moles of water are there?

5.5 moles

What is the pH of a solution with a H+ concentration of 1x10^-6

6

Erythrose, a 4 carbon sugar, has the following chemical formula

C4H8O4

place the following in the order from smallest to biggest

amino acid, triglyceride, lysosome, human fibroblast cell

What functional group is -N-H2

amino group

Which four elements make up approximately 96% of living matter?

carbon, nitrogen, oxygen, hydrogen

What is a false statement in terms of cellulose?

cellulose is a major food source for all animals because it is easily digested

When a protein is denatured, why does it lose its functionality?

denaturation breaks the weak bonds, such as hydrogen bonds, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function

In a beta sheet, a hydrogen atom participates in a covalent bond with a nitrogen atom of one amino acid and also weakly interacts with an oxygen atom of another amino acid. What is this second, weaker interaction called?

hydrogen bond

A molecule that has all nonpolar covalent bonds would be __________.

hydrophobic

What type of bond results from a complete transfer of electrons between atoms?

ionic bond

Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called?

isotopes

The scientific method usually begins with

making observations

The nucleus and mitochondria contain ___________, but the lysosome and cell wall do not

nucleic acid

What contains the vast majority of of the eukaryotic cell's DNA

nucleus

Where are the ribosomes assembled in eukaryotic cells?

nucleus

What type of linkage connects nucleotides units in RNA?

phoshpodiester linkages

What is the cytoskeleton composed of?

proteins

Insulin, a protein secreted by some pancreas cells, is made on

the rough endoplasmic reticulum

what is an example of a lipid?

triglyceride

how many and what type of bonds does sulfur usually form in biology?

two covalent bonds