Molecules and Fundamentals of Biology

Question 1

Phosphatase

Answer 1

An enzyme that cleaves/removes a phosphate group off a substrate molecule

Question 2

What does a large K_m suggest?

Answer 2

large amount of substrate is needed because enzyme availability is low

Question 3

Kinase

Answer 3

Enzyme that transfers a phosphate group from an ATP molecule to a substrate molecule, does NOT break bonds in order to add a phosphate group

Question 4

What does a small K_m suggest?

Answer 4

small amount of substrate is required because enzyme availability is high

Question 5

How are molecules formed?

Answer 5

When two or more atoms join together
Ex: oxygen gas (O₂)

joined together via interactions of electrons

Question 6

How are compounds formed?

Answer 6

When two or more atoms of at least 2 different elements join together

Question 7

During polymerization, what is added to the 3’ end of the sugar-phosphate backbone?

Answer 7

nucleoside triphosphate is added to the growing nuclei acid polymer by losing two phosphates as pyrophosphate, forming a phosphodiester bond with the free hydroxyl at the 3’ end of the polymer

Question 8

Feedback regulation

Answer 8

When the end product of a reaction pathway negatively inhibits an upstream (earlier) enzyme

Question 9

Biosynthetic reactions

Answer 9

Also known as anabolic reactions, convert substrates into more complex products in living organisms —> the products are more ordered and have a decreased entropy compared to their reactants

Example: photosynthesis converts solar energy into chemical energy - 6 carbon dioxide and water molecules produce fixed carbon in the form of glucose which is more complex and more ordered than water and carbon dioxide and has a decreased entropy compared to them

Question 10

what type of bond are glycosidic bonds?

Answer 10

covalent bonds

Question 11

what type of bonds are associated with tertiary structures of proteins?

Answer 11

• Due to non-covalent interactions between R-groups
• ionic bonding, hydrogen bonding, dipole-dipole interactions, london dispersion forces (Van der Waals forces) , hydrophobic interactions
• disulfide bridges (strong covalent bond between cysteines, contributes to 3D structure)

Question 12

what type of bonds are associated with primary structures of proteins?

Answer 12

• primary structure are linear sequences of amino acids linked via peptide bonds (covalent bonds) that attach between one amino acids carboxyl group and the other amino acids amino group

Question 13

waxes

Answer 13

• lipid derivative
• long fatty acid tails and monohydroxy alcohols joined together via ester linkages
• provides a hydrophobic protective coat
• ex: found on some plant leaf surfaces and some aquatic bird feathers

Question 14

carotenoid

Answer 14

• lipid derivative
• long carbon chains with conjugated double bonds with 6-membered ring on each end
• function as pigments, producing colors in plants and animals
• ex: carotenoid cerotene gives the yellow to orange color and xanthophylls

Question 15

porphyrins

Answer 15

• (tetrapyrroles)
• lipid derivative
• comprised of four joined pyrrole rings that are often complex with a metal ion
• ex: hemoglobin

Question 16

brown fat cells

Answer 16

• a type of adipocyte
• contain a considerable amount of cytoplasm, lipid droplet scattered throughout, and lots of mitochondria

Question 17

white fat cells

Answer 17

• a type of adipocyte
• composed primarily of triglycerides with a small layer of cytoplasm around it

Question 18

V_max is the:

Answer 18

maximal velocity of an enzyme

Question 19

globular proteins

Answer 19

• water-soluble
• dominated by tertiary structure
• contain a diverse range of functionality: enzymatic, hormonal, inter/intracellular storage and transport, osmotic regulation and immune response

Question 20

what property of water makes it a good biological solvent?

Answer 20

waters polarity caused by dipoles of H₂O break up charged ionic molecules, making it easy for water to dissolve substances

Question 21

what are the five important properties of water?

Answer 21

1) excellent biological solvent
2) high heat capacity
3) ice floats
4) cohesion/surface tension
5) adhesion

Question 22

adhesion propoerty of water:

Answer 22

• water is attracted to unlike substances as well
• ex: wetting finger to flip a page
• has capillary action: the ability to flow without external forces

Question 23

cohesion/surface tension propoerty of water:

Answer 23

• water is attracted to like substances due to its H-bonds
• water has strong cohesion between other water molecules which produces high surface tension that allows for bugs to walk on water

Question 24

heat capcity property of water:

Answer 24

• water has a high heat capacity
• heat capacity: ability to change temperature in response to gaining/losing heat
• water has stable temperatures in response to changes in surrounding temperatures, large amount of energy must be added to warm up water

heat capacity: changing temp. in response to gaining/losing heat

Question 25

ice floats propoerty of water:

Answer 25

* water expands as it freezes * becomes **less dense** than its liquid form * due to H-bonds becooming rigid, forming a crystal that keeps the molecules separated

Question 26

glucose +fructose

Answer 26

sucrose

Question 27

glucose + galactose

Answer 27

lactose

Question 28

glucose + glucose

Answer 28

maltose

Question 29

celll theory:

Answer 29

* all living organisms are composed of one or more cells * the cell is the basic unit of structure, function and organization in all organisms * all cells come from preexisting, living cells * cells carry hereditary information

Question 30

RNA world hypothesis

Answer 30

* self-replicating RNA molecules were the precursors to current life * RNA stores genetic information like DNA * RNA catalyzes chemical reactions like enzymes * RNA played a major role in the evolution of cellular life * hypothesis recieved support from the fact that RNA is unstable compared to DNA due to extra OH group --> makes it likely to participate in chemical reactions

Question 31

fibrous/structural proteins

Answer 31

* not water-soluble * dominated by secondary structure * made of long polymers * function to maintain and add strength to cellular and matrix structure * ex: collagen, keratin

Question 32

membrane proteins

Answer 32

* proteins that function as membrane pumps, channels or receptors

Question 33

cofactors

Answer 33

* non-protein molecules that assist enzymes * can be organic (vitamins) or inorganic (iron and magnesium)

Question 34

holoenzyme

Answer 34

* union of a cofactor and an enzyme

Question 35

apoenzyme

Answer 35

* when an enzyme is not combined with a cofactor

Question 36

coenzyme

Answer 36

* an organic cofactor * ex: vitamins

Question 37

prosthetic group

Answer 37

* a cofactor that is covalently bound to an enzyme

Question 38

simple proteins

Answer 38

* formed entirely of amino acids * ex: albumin and globulins: functional proteins that act as carriers or enzymes * ex: scleroprotein: fibrous proteins that have structural function (collagen)

Question 39

conjugated proteins

Answer 39

* simple protein + non-protein * lipoprotein: protein bound to lipid * mucoprotein: protein bound to carbohydrate * chromoprotein: protein bound to pigmented molecule * metalloprotein: protein complexed around metal ion * nucleoprotein: contains histone or protamine bound to nucleic acid