Biochemistry

Question 1

Organic molecules

Answer 1

• always contain carbon and hydrogen
• needed in order to keep our bodies functioning
• monomers such as glycerol, fatty acids, amino acids and nucleotides join together to form the polymers of lipids, proteins, and nucleic acids
• become complex because functional groups(a cluster of atoms that behave in specific ways)also attach to carbon atoms

Question 2

Carbon compounds

Answer 2

• has the potential to form many compounds therefore it’s the basis of most organic compounds
• can form simple structures such as methane to form chains as seen in fatty acids
• can also bond with itself to form a ring as seen in carbohydrates

Question 3

What are the four most common elements?

Answer 3

Carbon, hydrogen, oxygen, nitrogen

Question 4

Hydrogen bond

Answer 4

• occurs when a convalently bonded hydrogen is positive and attracted to another negatively charged atom
• water has negative and positive ends; electrons spend more time around the oxygen atoms, creating a slight negative charge on O and a positive charge on H
• represented by a dotted line( - - - )
• can strengthen the molecule(ice formation) or dissociate a molecule (hydrolysis)

Question 5

How is water a coolant?

Answer 5

• it takes more energy to break the bonds and release steam
• can store large amounts of heat
• can also evaporate thus allowing an organism to lose heat

Question 6

How does water regulate temperature?

Answer 6

• the hydrogen bonds cause water to absorb a great deal of heat before it boils
• water also holds heat so its temperature falls slowly

Question 7

How is water the universal solvent?

Answer 7

• the polarity of water can break apart molecules as the negative end (O) will pull apart the positive ions and vice versa
• when ions and molecules disperse in water, they move about and collide, allowing reactions to occur

Question 8

Why is water a good transport medium?

Answer 8

• water molecules cling together because of hydrogen bonding and yet water moves freely
• allows dissolved and suspended molecules to be evenly distributed throughout a system
• when water molecules evaporate they can pull through other dissolved molecules from behind

Question 9

Carbohydrates

Answer 9

• quick and short-term energy storage
• easily digested which makes their energy easy to obtain
• soluble in water so they are transported around the body easily
• formed with C, H, and O in different arrangements

Question 10

Glucose

Answer 10

• a monosaccharide(others include galactose and fructose)
• -the simplest carbon ring
• forms the base of carbs

Question 11

Starch

Answer 11

• a hydrocarbon carbon chain with few branches

- a way for plants to store glucose

Question 12

Glycogen

Answer 12

• hydrocarbon chain with many brances

- a way for animals to store glucose

Question 13

Cellulose

Answer 13

• hydrocarbon that has alternating positions of oxygen

- builds cell walls

Question 14

Dehydration synthesis

Answer 14

• occurs when 2 glucose molecules(monosaccharides) hook up to form a dissacharide(maltose, lactose, and sucrose)
• during the process a water molecule is released

Question 15

Hydrolysis

Answer 15

• occurs when water breaks up a molecule
• the addition of water leads to the disruption of the bonds linking the unit molecules tother
• requires the action of enzymes(hydrolytic enzymes)

Question 16

Functions of carbohydrates

Answer 16

• energy production(glucose=energy)
• energy storage(starch, glycogen)
• structural
• cell membrane markers(receptors)

Question 17

Lipids

Answer 17

• fats(fatty acids)
• phospholipids
• steroids

Question 18

Fats

Answer 18

• a hydrocarbon chain that ends with an acidic group (COOH)
• usually 16-18 carbons long with a double of O
• produced through condensation reaction where 3 water molecules are produced
• formed from glycerol plus fatty acids
• saturated bonds: solid at room temperature as it is more stable due to its hydrogen bonds; no double bonds; butter
• unsaturated fats: liquids like oils; double bonded carbon

Question 19

Phospholipids

Answer 19

• same structure as a fatty acid but contains a phosphate or nitrogen instead of an acidic acid
• replace one fatty acid in a triglyceride with a phosphate-containing group, this causes the molecule to be polar(hydrophillic)
• tail is non-polar (hydrophobic)

Question 20

Steroids

Answer 20

• contain a four-carbon ring that is fused together
• differ due to atomic ring arrangement and the functional group that is attached
• sex hormones, cholesterol

Question 21

Lipid functions

Answer 21

• long term energy storage(adipose tissue)
• insulation; subeutaneous and around major organs
• structure; cell membrane
• hormones; cholesterol, sex hormones
• leaf cuticle
• waterproof animal fur/feather
• neural impulse
• buoyancy in aquatic animals

Question 22

Proteins

Answer 22

• building blocks are amino acids
• macromolecules with amino acid monomers
• some proteins are enzymes which speed chemical reactions

Question 23

Polymerization

Answer 23

-occurs when a protein is formed
-when a chain of amino acids is created by bonding each amino acid together
-

Question 24

Peptides

Answer 24

• aka amino acids
• proteins are usually 50-75 amino acids long
• chains of 2 or more amino acids are called polypeptides(a single chain of amino acids)
• a condensation synthesis reaction between 2 amino acids results in a dipeptide and a molecule of water
• polypeptides can make use of 20 different amino acids
• each polypeptide has its own sequence of amino acids

Question 25

Peptide bond

Answer 25

• a bond that joins 2 amino acids
• elements that are involved are O, C, N, & H
• peptide bond is polar
• hydrogen bonding is possible between the C=O of 1 amino acid and the N-H of another amino acid in a polypeptide

Question 26

Protein level of structure

Answer 26

• primary: chain like sequence of amino acids joined by peptide chains
• secondary: twisting of primary structure into a helix; hydrogen bonds form between H & O of the backbone( weak bond); similar to winding staircase & pleated sheets
• tertiary: a complex folding of the secondary helix into a globular shape(3D shape); ionic bonds, covalent bonds, H-bonds, and S-S bonds between cysteines
• quatermary: more than one tertiary protein molecule bound together into a globular mass; held together by the same bonds found in the tertiary structure (e.g. hemoglobin)

Question 27

Protein functions

Answer 27

• structure; keratin(hair, nails), collagen
• enzymes; salivary anylase
• hormones; insulin
• transport; hemoglobin
• movement; actin & myosin(muscle cell)
• defense(immunoglobin)

Question 28

Protein denaturation

Answer 28

• occurs when proteins undergo an irreversible change in shape
• the loss of specific shape of a protein will cause it to lose its function properties
• can be done by temperature, pH, or chemicals(heavy metals)

Question 29

Nucleic acids

Answer 29

• chemicals that carry hereditary or genetic information

- huge macromolecular compounds that are polymers of nucleotides

Question 30

DNA

Answer 30

• makes up chromosomes and genes
• controls all cell activities
• undergoes mutations which contributes to evolution
• -4 different nucleotides; sequence of these nucleotides is the genetic code
• polymers of nucleotides that form from the dehydration synthesis between nucleotides

Question 31

RNA

Answer 31

• works with DNA to make proteins
• has 1 different nucleotide for a total of 5 different nucleotides
• polymers of nucleotides that form from the dehydration synthesis between nucleotides

Question 32

Nucleotides

Answer 32

-consist of a five carbon sugar (ribose/deoxyribose), a phophate, and a nitrogen containing base(1 or 2 rings)

Question 33

ATP

Answer 33

• energy currency for the cell

- a nucleotide but not part of a nucleic acid