Entrance Exam Semmelweis EXAM LATEST (2025) COMPLETE QUESTIONS With
100% Verified Solutions,
Proteoglycans - glycosaminoglycan + protein
- found in connective tissues
- form cartilage (with collagen)
- mostly carbohydrate
Glycerolipids - triglycerides - glycerol + 3 fatty acids (ester linkages); long-term energy storage
phosphoglycerolipids - glycerol based phospholipids; structural component of membrane
Types of rNA - mRNA (transcription), tRNA (translation), rRNA (ribosome), snRNA (used in
RNA processing)
Vitamins - fat soluble = A, D, E, K
water soluble = B, C
Reversible inhibition of enzyme activity - 1. competitive (binds to active site)
- Km increases, Vmax stays the same
2. noncompetitive (binds to allosteric site, changes enzyme's conformation)
- Vmax decreases, Km stays the same
3. uncompetitive (binds to enzyme-substrate complex)
- Vmax decreases, Km decreases
4. mixed (binds to either allosteric site or ESC)
,- Vmax decreases, Km increases or decreases
Allosteric inhibition - inhibitor binds to site other than active site & changes shape of enzyme
Covalent modifications of enzymes - 1. phosphoester formation
- phosphoryl group esterified to serine side chain
2. acetylation: increases transcription
- acetyl group added --> neutralizes charge of lysine --> more space between DNA and histone
3. deacetylation: decreases transcription
- acetyl group removed --> positive charge of lysine restored --> less space between DNA and
histone
4. methylation: decreases transcription
- blocks DNA
5. de-methylation: increases transcription
- removes methyl group so RNA polymerase can access DNA
DNA replication - multiple origins of replication in a chromosome
single-stranded DNA-binding protein stabilizes unwound template strands
1. helicase unwinds double helix
2. primase synthesizes RNA primers
3. DNA polymerases (alpha, delta, epsilon) synthesize DNA
, 4. RNase H (5'-->3' exonuclease) removes RNA primers
5. DNA polymerase delta replaces RNA with DNA
6. DNA ligase connects okazaki fragments
7. DNA topoisomerases remove supercoils before replication forks
8. telomerases synthesize telomeres
DNA repair mechanisms - 1. direct repair
- converts altered base back to original
2. excision repair
- mismatched base removed
3. postreplication repair
- undamaged chromosome repairs damaged one
Transcription - DNA --> mRNA
**initiation occurs when RNA polymerase binds to promoter
- assisted by transcription factors (e.g. TATA box)
Main enzyme = RNA polymerase II
Processing of mRNA - 1. splicing out introns, joining exons
- done by spliceosome (snRNA + snRNPs)
2. 5'-cap (guanine)
- ribosome recognizes this as binding site
100% Verified Solutions,
Proteoglycans - glycosaminoglycan + protein
- found in connective tissues
- form cartilage (with collagen)
- mostly carbohydrate
Glycerolipids - triglycerides - glycerol + 3 fatty acids (ester linkages); long-term energy storage
phosphoglycerolipids - glycerol based phospholipids; structural component of membrane
Types of rNA - mRNA (transcription), tRNA (translation), rRNA (ribosome), snRNA (used in
RNA processing)
Vitamins - fat soluble = A, D, E, K
water soluble = B, C
Reversible inhibition of enzyme activity - 1. competitive (binds to active site)
- Km increases, Vmax stays the same
2. noncompetitive (binds to allosteric site, changes enzyme's conformation)
- Vmax decreases, Km stays the same
3. uncompetitive (binds to enzyme-substrate complex)
- Vmax decreases, Km decreases
4. mixed (binds to either allosteric site or ESC)
,- Vmax decreases, Km increases or decreases
Allosteric inhibition - inhibitor binds to site other than active site & changes shape of enzyme
Covalent modifications of enzymes - 1. phosphoester formation
- phosphoryl group esterified to serine side chain
2. acetylation: increases transcription
- acetyl group added --> neutralizes charge of lysine --> more space between DNA and histone
3. deacetylation: decreases transcription
- acetyl group removed --> positive charge of lysine restored --> less space between DNA and
histone
4. methylation: decreases transcription
- blocks DNA
5. de-methylation: increases transcription
- removes methyl group so RNA polymerase can access DNA
DNA replication - multiple origins of replication in a chromosome
single-stranded DNA-binding protein stabilizes unwound template strands
1. helicase unwinds double helix
2. primase synthesizes RNA primers
3. DNA polymerases (alpha, delta, epsilon) synthesize DNA
, 4. RNase H (5'-->3' exonuclease) removes RNA primers
5. DNA polymerase delta replaces RNA with DNA
6. DNA ligase connects okazaki fragments
7. DNA topoisomerases remove supercoils before replication forks
8. telomerases synthesize telomeres
DNA repair mechanisms - 1. direct repair
- converts altered base back to original
2. excision repair
- mismatched base removed
3. postreplication repair
- undamaged chromosome repairs damaged one
Transcription - DNA --> mRNA
**initiation occurs when RNA polymerase binds to promoter
- assisted by transcription factors (e.g. TATA box)
Main enzyme = RNA polymerase II
Processing of mRNA - 1. splicing out introns, joining exons
- done by spliceosome (snRNA + snRNPs)
2. 5'-cap (guanine)
- ribosome recognizes this as binding site
