LECTURE 3: CHEMICAL COMPONENTS OF THE CELL

Question 1

what elements are important in cells?

Answer 1

hydrogen, carbon, nitrogen, sulphur, phosphorus

Question 2

an element’s atomic number represents..

Answer 2

the number of protons and respectively the number of electrons

Question 3

an element’s atomic weight is..

Answer 3

the number of protons and neutrons

Question 4

what is the difference between an element and an atom?

Answer 4

element: substance composed of one type of atom

atom: smallest particle of an element with distinctive chemical properties

Question 5

true or false: a molecule is 2+ chemically-joined atoms

Answer 5

true

Question 6

does a compound have to have 2 different elements?

Answer 6

yes

Question 7

what kind of bond is known for transferring electrons?

Answer 7

ionic bond

Question 8

covalent bonds are the result of..

Answer 8

sharing electrons

Question 9

true or false: carbon can form single, double, and triple bonds
- why?

Answer 9

true

• has 4 outer shell electrons

Question 10

why are covalent bonds stronger than non-covalent bonds?

Answer 10

there is more energy required to break them due to the release of energy during their formation

Question 11

true or false: single covalent bonds require more energy than double covalent bonds

Answer 11

false: double covalent bonds require more energy than single covalent bonds

Question 12

what type of covalent bond is formed when elections are shared unequally?

Answer 12

polar covalent bond

Question 13

polar covalent bonds have partial ___ and ___ charges or dipoles

Answer 13

positive and negative

Question 14

why are non-covalent interactions more preferable in a biological setting?

Answer 14

they are weak enough that they can be formed and re-formed at room temperature

Question 15

what does it mean for a covalent bond to be non-polar

Answer 15

electrons are being shared equally

Question 16

what are examples of non-covalent interactions? (intermolecular)

Answer 16

ionic/electrostatic

hydrogen bonds

van der waals

hydrophobic

Question 17

what is a hydrogen bond?

Answer 17

an electronegative ion bonded to a hydrogen atom that is already covalently linked to another electronegative atom

Question 18

which kind of bond is important in bringing molecules together in cells?

Answer 18

non-covalent bonds

Question 19

for each cellular organelle, name the types of macromolecules that are involved in their functions
1. nucleus
2. cell wall
3. plasma membrane
4. ribosome
5. mitochondrion
6. microtubules
7. chloroplasts

Answer 19

1. nucleic acid and protein
2. carbohydrates
3. carbohydrates, lipids, and proteins
4. protein and nucleic acid
5. lipids, protein, and nucleic acid
6. protein
7. carbohydrates

Question 20

what are the 4 large organic molecules of the cell?

Answer 20

1. polysaccharides, glycogen, starch or carbohydrates
2. fats and membrane lipids
3. proteins
4. nucleic acids

Question 21

what are the small building blocks of the cell that makeup macromolecules?

Answer 21

1. sugars
2. fatty acids
3. amino acids
4. nucleotides

Question 22

carbohydrates have a standard formula of..

Answer 22

(CH2O)n

Question 23

sugars have a basic role of..

Answer 23

being an energy source and being polysaccharide subunits

Question 24

regarding carbohydrates what examples serve as..

a. energy sources
b. structural integrity
c. signaling factors

Answer 24

a. glycogen and starch

b. cartilage and cellulose

c. glycolipids and glycoproteins

Question 25

oligosaccharides means..

Answer 25

2-10 sugar subunits

Question 26

regarding lipids,
fatty acids or hydrocarbon chains make up ..

Answer 26

fats and membrane lipids

Question 27

what do fatty acids form that serves as a slow-burning energy source?

Answer 27

triacylglycerol

Question 28

what does it mean for fatty acid tails to be saturated and unsaturated?

Answer 28

saturated: no doble bonds

unsaturated: double bonds

Question 29

the formations of bonds in fatty acids involve what kind of interactions?

Answer 29

non-covalent interactions

Question 30

membrane lipids participate in..

Answer 30

membrane structure and function

Question 31

what serves as the building blocks of proteins and polypeptides?

Answer 31

amino acids

Question 32

describe every amino acid’s basic structure

Answer 32

an alpha carbon

a carboxyl group

an amino group

a hydrogen attached to the alpha carbon

a R group/side chain

Question 33

what kind of bonds are formed between amino acids?

Answer 33

peptide bonds

Question 34

what are the 2 formations possible for amino acids?

Answer 34

L-formation and D-formation

mirrored images = enantiomers

Question 35

when is a polypeptide considered a protein?

Answer 35

when it has adapted a stable 3D shape and is biologically active/folded

Question 36

a 3D structure of a protein can be formed using ___ and ___ interactions

Answer 36

covalent and non-covalent

Question 37

what are the 4 structures involved in protein formation?

Answer 37

primary structure: amino acids

secondary structure: alpha helix

tertiary structure: polypeptide chain

quarternary structure: protein

Question 38

nucleotides serve as building blocks for..

Answer 38

nucleic acids like DNA and RNA

Question 39

what is the differences between nucleosides and nucleotides

Answer 39

nucleosides = a base + sugar

nucleotides = base+ sugar + phosphate

Question 40

what are the sugars you can see in nucleosides/nucleotides?

Answer 40

D-deoxyribose

D-ribose

Question 41

what are the bases you can see in nucleosides and nuclleotides?

Answer 41

purines: adenine + guanine

pyrimidines: cytosine + thymine + uracil

Question 42

what are the 2 main functions of nucleotides?

Answer 42

1. short term carriers of ATP
2. storage and retrieval of DNA and RNA

Question 43

what kind of reaction is common in macromolecule formation?

Answer 43

condensation reaction or a dehydration synthesis