Download Semmelweis Chemistry Entrance Exam New Latest 2024-2025 Version with All Questions and more Exams Chemistry in PDF only on Docsity!
Semmelweis Chemistry Entrance Exam New Latest
2024 - 2025 Version with All Questions from Actual
Exam and Correct Answer
How does absorption occur? ----------- Correct Answer ----------- diffusion, facilitated diffusion, osmosis, active transport How does absorption work? ----------- Correct Answer ----------- - food molecules are absorbed into the blood or the lymph. To be absorbed in the body the molecules need to pass into the capillaries or the villus. Fats absorb into the lymph
- Substances to be absorbed move from the lumen into the epithelial villi
- Amino acids and monosaccharides move from the villi into capillaries and monoglycerides move into the lacteals What are triglycerides? ----------- Correct Answer ----------- the main group of lipids. They are formed by condensation reactions between one glycerol and three fatty acids, creating ester bonds What are the main types of triglycerides? ----------- Correct Answer ----------- fats and oils. Fats are solid and oil liquid at room temp What is the driving force of natural processes? ------------ Correct Answer ----------- enthalpy H and entropy S What is the order of entropy and the state of matter? ------------ Correct Answer ----------- solid < liquid < gas What is reaction rate? ------------ Correct Answer ----------- The reaction rate is the speed at which a chemical reaction takes place What factors affect reaction rate? ------------ Correct Answer ----------- Reactant concentration, the physical state of the reactants, and surface area, temperature, and the presence of a catalyst What are fatty acids? ----------- Correct Answer ----------- carboxylic acids, possessing a - COOH functional group What are some of the digestive enzymes? ----------- Correct Answer ----------- - typsinogen and chymotrypsin (breaks down proteins)
- amylase breaks down starches and sugars
- lipase breaks down fats What are the parts of the respiratory system? ----------- Correct Answer -----------
What are the mechanisms of inhalation and exhalation? ----------- Correct Answer -------- --- When you inhale, the diaphragm contracts and moves downward. Through exhalation air leaves the lungs and the diaphragm relaxes How does the oxygen and CO2 exchange in the lungs occur? ----------- Correct Answer - ---------- Gas exchange is the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. The walls of the alveoli share a membrane with the capillaries in which oxygen and carbon dioxide move freely between the respiratory system and the bloodstream What are the parts of the excretory system? ----------- Correct Answer ----------- What are the parts of the circulatory system? ----------- Correct Answer ----------- What is the function of the heart? ----------- Correct Answer ----------- The heart is the most powerful muscle in the body, pumping 4,000 gallons of blood a day What is the structure of the heart? ----------- Correct Answer ----------- What is blood? ----------- Correct Answer ----------- fluid connective tissue What does blood contain? ----------- Correct Answer ----------- Nutrients such as glucose, antibodies, carbon dioxide, heat, oxygen, urea and hormones What are the different cell types? ----------- Correct Answer ----------- Prokaryotic and Eukaryotic What is the process of cellular immune response? ----------- Correct Answer ----------- the immune system's third line of defense, involving the attack of pathogens by T cells What are the three lines of defense? ----------- Correct Answer ----------- First line: Natural barriers: Skin and mucous membranes Second line: Inflammation Third line: Adaptive (acquired) immunity How does blood clotting occur? ----------- Correct Answer ----------- Clotting seals damaged vessels to prevent pathogenic entry
- Injured cells and platelets release clotting factors
- These factors convert prothrombin into thrombin
- Thrombin converts fibrinogen (soluble) into fibrin (insoluble)
- Fibrin forms a mesh of fibres that block the injured site - Clotting factors also cause platelets to become sticky and form a solid plug (called a clot), sealing the wound - This process of events is called a coagulation cascade
- Clot formation in coronary arteries lead to heart attacks
What are the pituitary gland hormones and what are their functions? ----------- Correct Answer ----------- The pituitary gland is about the size of a pea. It is located in the brain, and sits just behind the bridge of the nose. The pituitary gland is called the master gland of the endocrine system. This is because it controls many other hormone glands in the body What are the adrenal gland hormones and what are their functions? ----------- Correct Answer ----------- The adrenal cortex—the outer part of the gland—produces hormones that are vital to life, such as cortisol (which helps regulate metabolism and helps your body respond to stress) and aldosterone (which helps control blood pressure) What are the thyroid gland hormones and what are their functions? ----------- Correct Answer ----------- The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine and triiodothyronine Describe the autonomic nervous system ----------- Correct Answer ----------- The autonomic nervous system is the motor subdivision of the parasympathetic nervous system that controls body activities automatically. The ANS is composed of a specialized group of neurons that regulate the cardiac muscle, smooth muscles, and gland. The relative stability of the body is due to the ANS. What are spinal reflexes? ----------- Correct Answer ----------- simple pathways in the nervous system that rapidly generate muscle contractions Explain the functions of the spinal cord ----------- Correct Answer ----------- Its three major roles are to relay messages from the brain to different parts of the body, to perform an action, to pass along messages from sensory receptors to the brain, and to coordinate reflexes that are managed by the spinal cord alone What is the nerve cell structure? ----------- Correct Answer ----------- Each neuron contains a nerve cell body with a nucleus and organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus. Branching off the nerve cell body are the dendrites, which act like tiny antennae picking up signals from other cells Explain the resting and action potential of nerves ----------- Correct Answer ----------- The resting potential tells about what happens when a neuron is at rest. An action potential occurs when a neuron sends information down an axon, away from the cell body. ... When the depolarization reaches about - 55 mV a neuron will fire an action potential Explain the structure of the human eye ----------- Correct Answer ----------- What is the mechanism of vision? ----------- Correct Answer ----------- The light rays emitted by various objects are captured by eyes and then send inwards. The light rays are visible wavelength are focussed on the retina through the cornea & the lens. This generates the potentials (impulses) in the rods and the cones present in the retina
How does the hearing mechanism work? ----------- Correct Answer ----------- Sound waves enter the outer ear and travel through the external auditory canal until they reach the tympanic membrane, causing the membrane and the attached chain of auditory ossicles to vibrate How does the olfactory system function? ----------- Correct Answer ----------- involves the detection and identification of molecules in the air. Once detected by sensory organs, nerve signals are sent to the brain where the signals are processed What are mendel's laws? ----------- Correct Answer ----------- 1. Law of Dominance
- Law of Segregation
- Law of Independent Assortment What is the overall structure of genes? ----------- Correct Answer ----------- Genes are composed of deoxyribonucleic acid (DNA), except in some viruses, which have genes consisting of a closely related compound called ribonucleic acid (RNA). A DNA molecule is composed of two chains of nucleotides that wind about each other to resemble a twisted ladder What is a gene? ----------- Correct Answer ----------- segment of DNA that codes for a protein What are the levels of gene expression? ----------- Correct Answer ----------- Genes that code for amino acid sequences are known as 'structural genes'. The process of gene expression involves two main stages: Transcription: the production of messenger RNA (mRNA) by the enzyme RNA polymerase, and the processing of the resulting mRNA molecule What is a frameshift mutation? ----------- Correct Answer ----------- mutation that shifts the "reading" frame of the genetic message by inserting or deleting a nucleotide. The resulting protein is nonfunctional What is a missense mutation? ----------- Correct Answer ----------- Point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid. What is a nonsense mutation? ----------- Correct Answer ----------- change resulting in early stop codon What is a chromosomal mutation? ----------- Correct Answer ----------- A change in the number or structure of chromosomes What is down's syndrome caused by? ----------- Correct Answer ----------- trisomy 21 What is turner syndrome caused by? ----------- Correct Answer ----------- 45 chromosomes instead of 46
What are carbohydrates and lipids? ----------- Correct Answer ----------- Organic compounds that are mostly composed of three types of atom; carbon, hydrogen and oxygen What do carbohydrates do? ----------- Correct Answer ----------- provide energy, in the form of sugars like glucose and fructose, but they also make up structures like cellulose, which form the cell wall of plant cells What type of carbohydrate is the most important source of energy? ----------- Correct Answer ----------- mono-, di- and poly-saccharides What are mono and disaccharides? ----------- Correct Answer ----------- polar and soluble in water What are polysaccharides? ----------- Correct Answer ----------- Macromolecules resulting from polymerisation (condensation) of sugars and are not soluble in water Examples of monosaccharides ----------- Correct Answer ----------- ribose, glucose, fructose, galactose What forms a disaccharide? ----------- Correct Answer ----------- two monosaccharides linked together by condensation reactions with glycosidic bonds releasing one H2O molecule Alpha glucose structure ----------- Correct Answer ----------- Beta glucose structure ----------- Correct Answer ----------- Examples of Polysaccharides ----------- Correct Answer ----------- cellulose, glycogen and starch Monomer of Sucrose ----------- Correct Answer ----------- glucose and fructose monomer of maltose ----------- Correct Answer ----------- glucose and glucose monomer of lactose ----------- Correct Answer ----------- glucose and galactose monomer of starch ----------- Correct Answer ----------- glucose monomer of glycogen ----------- Correct Answer ----------- glucose monomer of cellulose ----------- Correct Answer ----------- glucose In animals, what carbohydrate stores energy? ----------- Correct Answer ----------- glycogen
What jobs do carbohydrates have other than storing energy? ----------- Correct Answer -- --------- structural components What differs the polysaccharides all made up of glucose? ----------- Correct Answer ------ ----- they differ in the arrangement of glucose molecules and position of the glycosidic bonds Starch arrangement ----------- Correct Answer ----------- amylopectin branched, amylose linear What is galactose? ----------- Correct Answer ----------- a sugar in milk What is fructose? ----------- Correct Answer ----------- a sugar found in fruit and honey Main characteristic of lipids? ----------- Correct Answer ----------- little to no affinity to water, mostly hydrophobic What are the simple forms of lipids? ----------- Correct Answer ----------- fat, oil and wax What are lipids characteristics in different solvents? ----------- Correct Answer ----------- they are non-polar and insoluble in water, but soluble in organic solvents What are the two basic forms of fatty acids? ----------- Correct Answer ----------- saturated and unsaturated What differs saturated from unsaturated fatty acids? ----------- Correct Answer ----------- Unsaturated fatty acids have double bonds; a monounsaturated having one, whereas a polyunsaturated having multiple What are cis and trans isomers? ----------- Correct Answer ----------- cis having the double bond elements on the same side, trans on opposite Benefit of lipids over carbohydrates? ----------- Correct Answer ----------- Lipids have a higher energy content and can act as thermal insulators What is the primary protein structure? ----------- Correct Answer ----------- the number and sequence of amino acids in a polypeptide What is the secondary protein structure? ----------- Correct Answer ----------- Beta pleated sheet and alpha helix. Hydrogen bonds between polypeptides form these structures What is the tertiary protein structure? ----------- Correct Answer ----------- three dimensional conformation. Forms when a polypeptide folds up after translation. Stabilized by intramolecular bonds between amino acids and polypeptides
diffuse back across the membrane to the matrix. ATP synthase uses the energy that the protons release as they diffuse down the concentration gradient to produce ATP What is the net yield of ATP in cellular respiration? ----------- Correct Answer ----------- 38 total 2 in glycolysis 2 in Krebs's cycle 34 in chemiosmosis (electron transport chain) What is DNA replication? ----------- Correct Answer ----------- the process of copying DNA What is DNA transcription? ----------- Correct Answer ----------- the organic process whereby the DNA sequence in a gene is copied into mRNA What is translation? ----------- Correct Answer ----------- the decoding of an mRNA message into amino acids which ultimately form protein what are the stages of transcription? ----------- Correct Answer ----------- Initiation, elongation, termination How does DNA replication occur? ----------- Correct Answer ----------- what is the nucleus ----------- Correct Answer ----------- A part of the cell containing DNA and RNA and responsible for growth and reproduction What are chromosomes? ----------- Correct Answer ----------- Chromosomes are long, thin strings composed of DNA and proteins which carry genes. What is the function of the endoplasmic reticulum? ----------- Correct Answer ----------- Modifies, packages, and transports proteins What is the function of the golgi apparatus? ----------- Correct Answer ----------- sorts and modifies proteins that have arrived from the rough ER What is the function of ribosomes? ----------- Correct Answer ----------- protein synthesis by translating mRNA What is the cytoskeleton? ----------- Correct Answer ----------- a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence. What is exocytosis? ----------- Correct Answer ----------- a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.
What is endocytosis? ----------- Correct Answer ----------- the taking in of matter by a living cell by invagination of its membrane to form a vacuole What is the function of a cell membrane? ----------- Correct Answer ----------- The cell membrane regulates what enters and leaves the cell and also protects and supports the cell Cell membrane diagram ----------- Correct Answer ----------- Describe the process of mitosis ----------- Correct Answer ----------- - Start with: Diploid, 2N
- Interphase: DNA replication = Dipoid, 4N
- Prophase: Condensation of chromatin, appearance of sister chromatids
- Metaphase: Sister chromatids align
- Anaphase: Sister chromatids separate, centromeres divide
- Telophase and Cytokinesis: Two identical, diploid, daughter cells: Diploid, 2N Describe the process of meiosis ----------- Correct Answer ----------- When a cell divides to form gametes:
- Copies of the genetic information are made
- The cell divides twice to form four gametes, each with a single set of chromosomes
- All gametes are genetically different from each other Gametes join at fertilisation to restore the normal number of chromosomes. The new cell divides by mitosis. The number of cells increases. As the embryo develops, cells differentiate. When does crossing over occur? ----------- Correct Answer ----------- prophase I of meiosis When does recombination occur in meiosis? ----------- Correct Answer ----------- during prophase I, when homologous chromosomes line up in pairs and swap segments of DNA. What is the structure of prokaryotic cells? ----------- Correct Answer ----------- Example of prokaryotic cell ----------- Correct Answer ----------- E. coli Example of eukaryotic cell ----------- Correct Answer ----------- plant and animal cells What is the structure of eukaryotic cells? ----------- Correct Answer -----------
What is autosomal? ----------- Correct Answer ----------- chromosomes that are not sex chromosomes What is connective tissue? ----------- Correct Answer ----------- Framework of the body, providing support and structure for the organs. What is included in connective tissue? ----------- Correct Answer ----------- Loose ordinary connective tissue Adipose tissue Blood and blood forming tissues Dense ordinary connective tissue Cartilage Bone What is the epithelium? ----------- Correct Answer ----------- A tissue that lines internal and external tissues in animals. Electron configuration for cations ----------- Correct Answer ------------ Subtract 1 from exponent of highest n-value orbital (ex. remove from 4s before 3d) Ag+ = [Kr]5s^1 4d^ Electron configuration for anions ----------- Correct Answer ------------ Add 1 to closest orbital Cl- = [Ne]3s^2 3p^ Atomic orbitals ----------- Correct Answer ------------ s, p, d, f Primary vs secondary structures of proteins ----------- Correct Answer ------------ Primary - AA chain (linked by peptide bonds) Secondary - stabilized by non-covalent bonds (alpha helices & beta sheets) Most bonds in organic compounds are ----------- Correct Answer ------------ covalent Properties of water ----------- Correct Answer ------------ 1. polar
- capable of adhesion and cohesion
- high heat capacity (so it's hard to raise its temp)
- great solvent
- high heat of vaporization (allows humans to cool off via sweat)
- water is less dense as a solid than a liquid Intermolecular forces of water ----------- Correct Answer ------------ hydrogen bonding
Solution components ----------- Correct Answer ------------ 1. solvent (product being dissolved)
- solute (medium for dissolving solvent) Molarity ----------- Correct Answer ------------ the number of moles of solute per liter of solution Solubility rules ----------- Correct Answer ------------ SOLUBLE
- alkali metals (group 1) & NH4+ cations
- NO3- or CH3COO- anions
- Cl, Br, I (except when bonded to Ag+, Pb2+ or Hg2+)
- sulfate ions (except when with Ca2+, Sr2+, Ba2+, Pb2+) INSOLUBLE
- Metal oxides (except CaO, SrO, BaO)
- Hydroxides (except when with Ca2+, Sr2+, Ba2+)
- Carbonates, phosphates, sulfides, and sulfites (unless bound to alkali metal or NH4+) Solubility product ----------- Correct Answer ------------ Ksp = [A]^a[B]^b **only products because we don't include solids in the equilibrium expression for NaCl
- Ksp = x^ for PbCl
- Ksp = 4x^ for Cr(OH)
- Ksp = 27x^ Large Ksp means ----------- Correct Answer ------------ strong electrolyte (more soluble) Strong acids ----------- Correct Answer ------------ So I brought no clean clothes
- H2SO
- HI
- HBr
- HNO
- HCl
- HClO
- HClO Strong bases ----------- Correct Answer ------------ 1. NaOH
- LiOH
- KOH
reducing agents cause reduction (they are oxidized) Voltaic cell ----------- Correct Answer ------------ AKA galvanic cell Spontaneous, supply energy
- reaction with higher E is reduced (cathode)
- ex. Zn and Cu connected by salt bridge Electrons flow from anode --> cathode Energy flows from cathode --> anode Reduction potential ----------- Correct Answer ------------ Cathode minus anode For voltaic cells, the higher value is the cathode **cathode is reduced, anode is oxidized Effects of temperature, pressure and concentration on reduction potentials ----------- Correct Answer ------------ Increased concentration --> decreased Ecell **temperature and pressure affect reduction potential ΔG = ΔH - TΔS = - nFEcell Biological roles of heme ----------- Correct Answer ------------ 1. carrying oxygen
- transporting/storing electrons Heat of chemical reactions ----------- Correct Answer ------------ ΔH = bonds broken - bonds formed Hess's law Gibbs free energy equation ----------- Correct Answer ------------ ΔG = ΔH - TΔS Entropy ----------- Correct Answer ------------ spontaneous dispersal of energy (S of universe is always increasing) **positive when bonds break, negative when bonds form Driving forces of natural processes are ----------- Correct Answer ------------ entropy and enthalpy Rate law vs. Keq ----------- Correct Answer ------------ rate law
- how fast reaction gets to equilibrium
- reactants only
- only depend on temperature & catalysts Keq
- where equilibrium lies
- [products]/[reactants] Catalysis ----------- Correct Answer ------------ lowering of activation energy by a catalyst Saturated vs unsaturated hydrocarbons ----------- Correct Answer ------------ unsaturated has double bond saturated is all single bonds (saturated by hydrogens) Imine formation ----------- Correct Answer ------------ ketone + primary amine **acid catalyzed (H+) Amine reactions ----------- Correct Answer ------------ 1. amine + acid --> ammonium salts
- aldehyde/ketone + 1˚ amine --> Schiff base (imine)
- aldehyde/ketone + 2˚ amine --> enamine Phosphate esters ----------- Correct Answer ------------ form nucleic acids & phospholipids High energy bonds
- store energy from food metabolism & use it for processes such as muscle contraction Schiff base ----------- Correct Answer ------------ primary amine + aldehyde/ketone --> imine Sulfur atoms in biomolecules ----------- Correct Answer ------------ disulfide - bonds between cysteine AAs; increase stability thiols - protect against oxidative stress thioesters - important in metabolism (e.g. Acetyl-CoA); transfer of acyl groups Structure and function of steroids ----------- Correct Answer ------------ structure
- derived from terpenes
- 3 hexagons, 1 pentagon function
- hormones with slow, long-lasting effects ex. cholesterol (vitamin D precursor, mediates cell membrane fluidity) Cholesterol is precursor to ----------- Correct Answer ------------ vitamin D + steroid hormones (e.g. testosterone, estradiol, cortisol, aldosterone, etc.)
negatively charged = aspartate, glutamate Peptide bonds ----------- Correct Answer ------------ formation
- condensation reaction (nucleophilic amino group attacks electrophilic carbon)
- water lost (so its a dehydration rxn) broken through
- hydrolysis (cleaving a bond with water) Purines vs pyrimidines ----------- Correct Answer ------------ purines = adenine & guanine
- hexagon and pentagon pyrimidines = thymine, cystosine, uracil
- just a hexagon
- thymine is uracil with a methyl group Building blocks of nucleotide ----------- Correct Answer ------------ nucleoside (pentose sugar & phosphate) + nitrogenous base Nucleic acids connected by ----------- Correct Answer ------------ phosphodiester bonds **complementary strands connected by H-bonds What is used to synthesize amino acids ----------- Correct Answer ------------ strecker synthesis (Aldehyde/ketone, NH4Cl, KCN) Protein structure levels ----------- Correct Answer ------------ primary - linear AA sequence secondary - hydrogen bonds stabilize structure (alpha helices, beta sheets) tertiary - hydrogen bonding, hydrophobic interactions, disulfide bonds, salt bridges (acid-base interactions)
- 3D conformation when polypeptide folds post-translation quaternary - multiple subunits; can be held together through salt bridges, H-bonds Polysaccharide structure ----------- Correct Answer ------------ polymer of monosaccharides
- starch
- amylose (linear, alpha 1, 4 bonds)
- amylopectin (branched, alpha 1,6 bonds & alpha 1,4 bonds)
- glycogen (very branched, only alpha 1,6 bonds)
- cellulose (beta 1,6 bonds, indigestible, very stable) Chemically modified carbohydrates ----------- Correct Answer ------------ Glycoproteins - oligosaccharide chain + protein
- found on cell surface
- cell to cell signaling
- mostly protein Proteoglycans - glycosaminoglycan + protein
- found in connective tissues
- form cartilage (with collagen)
- mostly carbohydrate Glycerolipids ----------- Correct Answer ------------ triglycerides - glycerol + 3 fatty acids (ester linkages); long-term energy storage phosphoglycerolipids - glycerol based phospholipids; structural component of membrane Types of rNA ----------- Correct Answer ------------ mRNA (transcription), tRNA (translation), rRNA (ribosome), snRNA (used in RNA processing) Vitamins ----------- Correct Answer ------------ fat soluble = A, D, E, K water soluble = B, C Reversible inhibition of enzyme activity ----------- Correct Answer ------------ 1. competitive (binds to active site)
- Km increases, Vmax stays the same
- noncompetitive (binds to allosteric site, changes enzyme's conformation)
- Vmax decreases, Km stays the same
- uncompetitive (binds to enzyme-substrate complex)
- Vmax decreases, Km decreases
- mixed (binds to either allosteric site or ESC)
- Vmax decreases, Km increases or decreases Allosteric inhibition ----------- Correct Answer ------------ inhibitor binds to site other than active site & changes shape of enzyme Covalent modifications of enzymes ----------- Correct Answer ------------ 1. phosphoester formation
- phosphoryl group esterified to serine side chain
