Biological Molecules (basics) Flashcards
(36 cards)
What’s an element?
A compound composed of one type of atom
What does pure carbon consist of?
Only of atoms with six protons and six electrons
How many bonds has Carbon typically got and where is it found?
4 bonds
Carbohydrates, lipids, proteins, & nucleic acids
How many bonds has Hydrogen typically got and where is it found?
1 bond
Is found in carbohydrates, lipids, proteins and nucleic acids
How many bonds has Oxygen typically got and where is it found?
2 bonds
Carbohydrates, lipids, proteins and nucleic acids
How many bonds has Nitrogen typically got and where is it found?
3 bonds
Proteins and nucleic acids
How many bonds has Sulphur typically got and where is it found?
3-5 bonds
Proteins
How many bonds has Phosphorus typically got and where is it found?
2 bonds
Nucleic acids
What are other important elements?
Sodium, potassium, calcium & iron
How do atoms connect with one another?
By forming bonds
Molecules contain more than one atom which are connected together by?
Intramolecular bonds (bond within the same molecule)
Molecules can be either?
Elements (oxygen gas O2 or Nitrogen gas N2)
OR
Compounds - which comprise more than one element (glucose C6H12O6)
what depends on the way that atoms bond with one another?
Depends on the number of electrons in the outer orbital of the atom
Compounds can have either bonds?…
Covalent bonds (C6H12O6)
Or
Ionic bonds (NaCl)
Explain covalent bonding
A covalent bond occurs when two atoms share a pair of electrons
The electrons used to form the bond are unpaired and present in the outer orbital of the atom
Give an example of when the sharing is equal
Oxygen gas (O2)
give an example of when the sharing is unequal
water (H2O)
Explain how unequal electron sharing works
When the sharing of the electrons is unequal, the atom that has the greater share of electrons becomes slightly negatively charged (delta-, meaning slight negative charge)
The Atom that has the lesser share of the electrons becomes slightly positively charged (delta+)
what does a molecule having a polar nature mean?
Where electrons are unequally share a molecule
(Water because of the unequal sharing of electrons)
What happens in ionic bonding?
One atom in the pair donates an electron and the other receives it.
This forms positive and negative ions that are held together by the attraction of the opposite charges
CATIONS=
Positively charged ions
ANIONS
Negatively charged ions
Why are ionic compounds not molecules?
Because ionic compounds have ions arranged in a giant lattice structure even in solid state.
So each of the Ion is attracted to many oppositely charged ions around it.
It is not possible to pin point which of the ion is linked to which particular ions
So ionic compounds do not exist as molecules
What are calcium ions necessary for?
- nerve impulse transmission
- muscle contraction
