Cytology

Question 1

Most abundant atoms in cells are:

Answer 1

C,H,N and O

Question 2

Most abundant constituent in a cell is:

Answer 2

Water/H2o

Question 3

Hydrogen bonds are:

Answer 3

Weak bonds(20x weaker than a covalent bond) due to partial charge on oxygen and hydrogen atoms(between H and O)

Question 4

Main 4 classes of organic compounds are:

Answer 4

Lipids-Protiens Carbohydrates- Nucleic acids

Question 5

Dry weight of cell is composed of mainly ……..

Answer 5

About55-85% protein

Question 6

Proteins are made by:

Answer 6

Polypeptide chains

Question 7

Polypeptides are made by:

Answer 7

Amino acids (20 types)

Question 8

Amino group is……..Carboxyl group is ……

Answer 8

Weak base ; weak acid

Question 9

C&

Answer 9

C chiral

Question 10

Amino acid origins

Answer 10

11 are synthesized by our body 9 from our diet

Question 11

4 classes of amino acids

Answer 11

Polar-Nonpolar-Basic A.a-Acidic A.a.

Question 12

Peptide bond chemical name is:

Answer 12

Amide bond between CO and NH

Question 13

Polypeptide synthesized by:

Answer 13

Ribosomes

Question 14

Primary structure of proteins is due to:

Answer 14

Sequence of nucleotides

Question 15

Secondary structure is result of :

Answer 15

Primary structure and the folding back of a.a chain

Question 16

Secondary structures main types are :

Answer 16

Helical shape or β-pleated sheets

Question 17

Tertiary structure is:

Answer 17

The way helical and non helical regions fold back each other until we have globular shape or cylindrical and so on .Determined by secondary and primary structures

Question 18

Disulfide bond is:

Answer 18

Very strong and stable bond between S-S (Disulfide bridge).

Question 19

Tertiary structure is stabilized by:

Answer 19

Sulfide bonds -ionic bonds -salt bridge-hydrogen bonds .

Question 20

Protein denaturation occurs due to:

Answer 20

Temperature change or ph change or by chemical agents and is usually irreversible.(if tertiary structure is lost then function is lost too)

Question 21

Quaternary structure is:

Answer 21

Protein subunits assemble with each other as some aren’t active in the tertiary state.Multiple subunits(identical or not) assemble to make active protein like Hemoglobin(2β chains-2α chains).

Question 22

Proteins exist in two possible conformations:

Answer 22

Active and Inactive

Question 23

Hetero-Proteins are:

Answer 23

ApoProtein+Lipid
ApoProtein+Carbohydrates
ApoProtein+non-protein molecules

Question 24

Several functions of proteins include

Answer 24

Defense Proteins(antibodies)
Structural Proteins(actin-myosin)
Contraction proteins (actin myosin)

Question 25

Monosaccharides are:

Answer 25

Simple Oses with general formula CnH2nOn(n=3-6)
OSES always unbranched

Question 26

Carbs are …….. diverse than proteins

Answer 26

Less

Question 27

Most monosaccharides have:

Answer 27

Aldehyde or ketone groups

Question 28

Monosaccharides can occur as:

Answer 28

Cyclic(more stable)or open

Question 29

Cyclic monosaccharides show two forms:

Answer 29

α and β

Question 30

Monosaccharides modifications such as Osamines are:

Answer 30

Replace Oh group with amino group example:galactose +amino=
Galactosamine also if we add acetyl then it is called
N-acetylGalactosamine

Question 31

Dimers and Polymers of monosaccharides are:

Answer 31

Monosaccharides assemble into dimers By Glycosidic Bonds ex:(Disaccharide)
Lactose=glucose+galactose

Question 32

Glycosidic bond is:

Answer 32

Between C4 and C6 and results in H2O

Question 33

Oligosaccharides are:

Answer 33

Short polymers of monosaccharides 10-20 (branches or not) maybe be linked to proteins

Question 34

Polysaccharides are:

Answer 34

Complex carbohydrates made up of monosaccharides and/or modified monosaccharides (long chains)

Question 35

Homopolysaccharides are:

Answer 35

Polymer made of same monosaccharides like starch has α-D-glucose

Question 36

HeteroPolysaccharides are:

Answer 36

Usually unbranched made up of 2 different or modified monosaccharides like keratanes or GAG(ex:Hyaluronan)

Question 37

Lipids

Answer 37

Not soluble in water but are in non polar organic solvent such as soap -acetone.

Question 38

Two major functions of lipids are :

Answer 38

Structural(cell membranes50%weight of it) and energetic(adipose)

Question 39

Lipids are hormones

Answer 39

Estrogen progesterone testosterone(steroids)