PP Ch. 2 Flashcards Preview

Cell Biology > PP Ch. 2 > Flashcards

Flashcards in PP Ch. 2 Deck (18)
Loading flashcards...
0
Q

Why do electrons matter?

A

Whether an atom will interact with other atoms depends on how many electrons it has

1
Q

What atoms are life’s chemical basis?

A

Protons, neutrons , electrons

2
Q

How to electrons move around the nuclei?

A

They move in orbitals

3
Q

What are the three most common types of bonds?

A

Ionic, covalent and hydrogen

4
Q

What is an ionic bond?

A

Weak bond. Ions stay together because of mutual attraction of opposite charges, have a large difference in electronegativity

5
Q

What is a covalent bond?

A

Two atoms with similar electronegativity and unpaired electrons sharing a pair of electrons. Stronger than ionic bond. Can share one, two or three pairs of electrons

6
Q

What are the two types of covalent bonds and give a short explanation

A
  1. Non polar covalent bond : share electrons equally. Formed between atoms with identical electronegativity
  2. Polar covalent bond :
    Atoms with different electronegativity do not share electrons equally. One atom is more neg other is more pos
7
Q

What is polarity?

A

Separation of charge into distinct positive and negative regions in a polar covalent molecule

8
Q

What is a hydrogen bond

A

A weak attraction between a highly electronegative atom and a hydrogen atom taking part in a seperate polar covalent bond. Not a chemical bond. Not a molecule. Stabilizes structures of proteins and DNA

9
Q

Where did life originate ?

A

Life originated in water.

10
Q

Does water have a charge?

A

No water does not have a charge

11
Q

Is a water molecule polar or non polar? And why

A

Water molecule is polar because oxygen atom is slightly negative and hydrogen atom is slightly positive

12
Q

Are polar molecules hydrophobic or hydrophilic?

A

Hydrophilic

13
Q

Are non polar molecules hydrophilic or hydrophobic?

A

They’re hydrophobic

14
Q

Are nonpolar molecules able to be dissolved by water?

A

No, only polar molecules

15
Q

What is specific heat?

A

Heat needed to raise temp by 1 degree

16
Q

What is cohesion?

A

When molecules resist separating from each other

17
Q

Why don’t marine life forms freeze in the winter?

A

Because ice is less dense than water and freezes ontop of the water