intro to biological molecules

Question 1

how many bonds can carbon form

Answer 1

Carbon (C) is the basis of living material because of its ability to form four bonds with

• other atoms
• and/or wide variety of chemical groups

Question 2

what form can carbon based molecules come in

Answer 2

simple, chain, or ring

Question 3

what bounds are present in carbon-based compounds?

Answer 3

• Carbon-based molecules are often large

* Held together by strong covalent bonds

Question 4

how many sub-atomic particals of protons, neutrons and electrons in carbon?

Answer 4

6 Protons
6 Neutrons
6 Electrons

Question 5

carbon bonding with flourine

Answer 5

CF4 one F shares one electron, in total carbon shares four of its electrons .

Question 6

what are the importance of functional groups attached to carbon based compounds.
what occurs when covalent bonds break?

Answer 6

• Clusters of atoms (functional groups) can attach to carbon-based compounds
• Each type of functional group has specific chemical properties
• Cellular chemical reactions often involve functional group transfer (loss or gain)
• Breakage of covalent bonds in carbon-based compounds releases energy

Question 7

what are te four most important macromolecules

Answer 7

o carbohydrates
o lipids
o proteins
o nucleic acids

Question 8

what are the polymers of these monomers:
suger
amino acid
nucleotide

Answer 8

• Macromolecules are composed of building blocks or subunits known as monomers
• Monomers join together with covalent bonds to form long chains or macromolecules known as polymers

polysaccharide
proteins
nucleic aciid

Question 9

how are polymers formed

Answer 9

• Formed by a type of condensation reaction known as dehydration synthesis
• A molecule of water is formed and removed from the reactants joined during the reaction

Question 10

how is a new covalent bond formed in a condensation reaction.

Answer 10

• Using energy generated by nearby reactions, a new covalent bond forms between the reactants

Question 11

how is water formed in a condensation reaction?

Answer 11

• H2O is formed from the loss of a hydroxyl group (-OH) from one reactant and a hydrogen (-H) from the other

Question 12

what is the name of the process that breaks down polymers?

Answer 12

• Polymers are broken down by an opposite process known as hydrolysis
• Bonds between reactants are broken with the addition of a molecule of water H2O

Question 13

how does hydrolysis release ATP

Answer 13

• The hydroxyl (-OH) group of a water molecule bonds with one reactant, and the hydrogen (-H) bonds to its neighbour
• The energy held in the bond is released and stored in the form of ATP

Question 14

Digestion of polymers

Answer 14

• Polymers like starch are broken down into smaller sugar units which are easily absorbed across the gut
• This hydrolysis reaction requires help from digestive enzymes

Question 15

biological molecules consist of which chemicals?

Answer 15

70% water
4% ions and small molecules
2% phospholipids
1% DNA
6% RNA
15% proteins
2% polysaccharides

Question 16

why is water vital for life?

Answer 16

• Chemical formula H2O
• Water is the most abundant molecule in your body
o 60-95% of fresh mass of living organisms
• Water is the medium in which cellular chemical reactions occur
• Water plays a major role in living systems
o Growth and reproduction
o Hydration, nutrition, hygiene and health

Question 17

what properties does water have

Answer 17

• Is a universal solvent and transporter
o All body fluids are mostly water
o Aids movement of chemicals during diffusion

• Is a lubricant
o In joints and on tissues
o Moistens epithelial surfaces
o Shock absorber

• Regulates body temperature
o Water requires heat to turn to vapour
o Sweat absorbs heat from the skin when evaporating

Question 18

what is the structure of water molecule?

Answer 18

• A simple molecule

* One oxygen atom bonded by single covalent bonds to two hydrogen atoms

Question 19

how much do you need of water

Answer 19

• The body tissues are 62% water

* Need approx 1.5L per day

Question 20

what does dehydration do to the body

Answer 20

• Dehydration is associated with many conditions, e.g. diarrhoea
• Dehydration can be fatal and must be rapidly treated
• Fluid replacement therapy – oral or IV

capillary refill test on a child to check hydration status

Question 21

how does polarity arise in water

Answer 21

• The oxygen atom contains eight positively charged protons (+) in its nucleus
• Each hydrogen atom contains only one positively charged proton (+) in their nucleus
• The electron pair shared in each O-H covalent bond is therefore more strongly attracted to the oxygen nucleus than to either of the hydrogen nuclei
• This makes the water molecule polar with a slightly negative pole near the oxygen (-) and a slightly positive pole near the hydrogen (+)

Question 22

how does hydrogen bonding occur in water

Answer 22

• The + near the hydrogen atoms is attracted to the - near the oxygen atom of a nearby water molecule
• This results in the formation of a hydrogen bond between two water molecules

Question 23

Why is water a liquid?

Answer 23

• Hydrogen bonds are weak (5% to 10% the strength of covalent bonds) and are easily broken (each lasts only 1/100,000,000,000 of a second)
• Hydrogen bonding creates a fluid as molecules constantly change partners

Question 24

Water is a Powerful Solvent

Answer 24

• Sodium chloride (salt) is a lattice of sodium (Na+) ions ionically bonded to chloride (Cl-) ions
• The + hydrogens are attracted to the Cl- ions, while the - oxygens are attracted to the Na+ ions
• The lattice pulls apart and the salt dissolves in the water

Question 25

why is water considered universal solvent?

Answer 25

• All polar (charged) molecules and ions are water soluble because they can form hydrogen bonds with water
• Ions and polar molecules can move/interact freely and take part in cellular chemical reactions

Question 26

what properties do nonpolar molecules have?

Answer 26

• Nonpolar molecules have no electrical charge and cannot form hydrogen bonds with water
• Nonpolar molecules repel water molecules and are thus hydrophobic whereas polar molecules attract water and are hydrophilic. Some complex molecules have a mixture of both properties and are amphiphilic
• The 3D shape of many biological molecules is influenced by hydrophobic forces

Question 27

how are alveoli prevented from collapsing

Answer 27

• Surface tension tends to make lung alveoli collapse

• Alveoli
secrete a non-polar ‘surfactant’ to break the surface tension

Question 28

how does surface tension occur

Answer 28

a. Causes surface layer of liquid to act as an elastic sheet

b. Caused by inter-molecular attractions between water molecules

Question 29

How surfactant prevents atelectasis in premature babies

Answer 29

c. Lungs create non-polar ‘surfactant’ to break the surface tension in the alveoli. Helps prevents atelectasis in premature babies by prevent the formation of surface tension to occur in alveoli