3.1 Biological elements

Question 1

Molecules are built from what?

Answer 1

from even smaller components called atoms

Question 2

Atoms are built from

Answer 2

yet smaller components including protons, neutrons and electrons

Question 3

How do atoms connect with each other?

Answer 3

by forming bonds

Question 4

How is a molecule formed?

Answer 4

when two or more atoms bond together

Question 5

When does a covalent bond occur?

Answer 5

when two atoms share a pair of electrons. The electrons used to form bonds are unpaired and present in the OUTER ORBITALS of the atoms

Question 6

Bonding is determined by the number of unpaired electrons present in the outer orbitals of different elements

Answer 6

C- 4 bonds
N- 3 bonds
O- 2 bonds
H- 1 bond

Question 7

In ionic bonds…

Answer 7

positive and negative ions are held together by the attraction of opposite charges

Question 8

What are the elements in carbohydrates

Answer 8

carbon, hydrogen and oxygen

Question 9

What are the elements in lipids

Answer 9

carbon, hydrogen and oxygen

Question 10

What are the elements in proteins

Answer 10

carbon, hydrogen, oxygen, nitrogen and sulfur

Question 11

What are the elements in nucleic acids

Answer 11

carbon, hydrogen, oxygen, nutrogen, and phosphorus