Cytology Flashcards
Basics of cell biology.
Most abundant atoms in cells are:
C,H,N and O
Most abundant constituent in a cell is:
Water/H2o
Hydrogen bonds are:
Weak bonds(20x weaker than a covalent bond) due to partial charge on oxygen and hydrogen atoms(between H and O)
Main 4 classes of organic compounds are:
Lipids-Protiens Carbohydrates- Nucleic acids
Dry weight of cell is composed of mainly ……..
About55-85% protein
Proteins are made by:
Polypeptide chains
Polypeptides are made by:
Amino acids (20 types)
Amino group is……..Carboxyl group is ……
Weak base ; weak acid
C&
C chiral
Amino acid origins
11 are synthesized by our body 9 from our diet
4 classes of amino acids
Polar-Nonpolar-Basic A.a-Acidic A.a.
Peptide bond chemical name is:
Amide bond between CO and NH
Polypeptide synthesized by:
Ribosomes
Primary structure of proteins is due to:
Sequence of nucleotides
Secondary structure is result of :
Primary structure and the folding back of a.a chain
Secondary structures main types are :
Helical shape or β-pleated sheets
Tertiary structure is:
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
Disulfide bond is:
Very strong and stable bond between S-S (Disulfide bridge).
Tertiary structure is stabilized by:
Sulfide bonds -ionic bonds -salt bridge-hydrogen bonds .
Protein denaturation occurs due to:
Temperature change or ph change or by chemical agents and is usually irreversible.(if tertiary structure is lost then function is lost too)
Quaternary structure is:
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).
Proteins exist in two possible conformations:
Active and Inactive
Hetero-Proteins are:
ApoProtein+Lipid
ApoProtein+Carbohydrates
ApoProtein+non-protein molecules
Several functions of proteins include
Defense Proteins(antibodies)
Structural Proteins(actin-myosin)
Contraction proteins (actin myosin)
Monosaccharides are:
Simple Oses with general formula CnH2nOn(n=3-6)
OSES always unbranched
Carbs are …….. diverse than proteins
Less
Most monosaccharides have:
Aldehyde or ketone groups
Monosaccharides can occur as:
Cyclic(more stable)or open
Cyclic monosaccharides show two forms:
α and β
Monosaccharides modifications such as Osamines are:
Replace Oh group with amino group example:galactose +amino=
Galactosamine also if we add acetyl then it is called
N-acetylGalactosamine
Dimers and Polymers of monosaccharides are:
Monosaccharides assemble into dimers By Glycosidic Bonds ex:(Disaccharide)
Lactose=glucose+galactose
Glycosidic bond is:
Between C4 and C6 and results in H2O
Oligosaccharides are:
Short polymers of monosaccharides 10-20 (branches or not) maybe be linked to proteins
Polysaccharides are:
Complex carbohydrates made up of monosaccharides and/or modified monosaccharides (long chains)
Homopolysaccharides are:
Polymer made of same monosaccharides like starch has α-D-glucose
HeteroPolysaccharides are:
Usually unbranched made up of 2 different or modified monosaccharides like keratanes or GAG(ex:Hyaluronan)
Lipids
Not soluble in water but are in non polar organic solvent such as soap -acetone.
Two major functions of lipids are :
Structural(cell membranes50%weight of it) and energetic(adipose)
Lipids are hormones
Estrogen progesterone testosterone(steroids)
