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Semmelweis Entrance Exam Medicine Biology 202 5
Guide
What are carbohydrates and lipids? - ANS-Organic compounds that are mostly composed of three types of atom; carbon, hydrogen and oxygen What do carbohydrates do? - ANS-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? - ANS-mono-, di- and poly-saccharides What are mono and disaccharides? - ANS-polar and soluble in water What are polysaccharides? - ANS-Macromolecules resulting from polymerisation (condensation) of sugars and are not soluble in water Examples of monosaccharides - ANS-ribose, glucose, fructose, galactose What forms a disaccharide? - ANS-two monosaccharides linked together by condensation reactions with glycosidic bonds releasing one H2O molecule Alpha glucose structure - ANS- Beta glucose structure - ANS- Examples of Polysaccharides - ANS-cellulose, glycogen and starch Monomer of Sucrose - ANS-glucose and fructose monomer of maltose - ANS-glucose and glucose monomer of lactose - ANS-glucose and galactose monomer of starch - ANS-glucose monomer of glycogen - ANS-glucose monomer of cellulose - ANS-glucose In animals, what carbohydrate stores energy? - ANS-glycogen
What jobs do carbohydrates have other than storing energy? - ANS-structural components What differs the polysaccharides all made up of glucose? - ANS-they differ in the arrangement of glucose molecules and position of the glycosidic bonds Starch arrangement - ANS-amylopectin branched, amylose linear What is galactose? - ANS-a sugar in milk What is fructose? - ANS-a sugar found in fruit and honey Main characteristic of lipids? - ANS-little to no affinity to water, mostly hydrophobic What are the simple forms of lipids? - ANS-fat, oil and wax What are lipids characteristics in different solvents? - ANS-they are non-polar and insoluble in water, but soluble in organic solvents What are triglycerides? - ANS-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? - ANS-fats and oils. Fats are solid and oil liquid at room temp What are fatty acids? - ANS-carboxylic acids, possessing a - COOH functional group What are the two basic forms of fatty acids? - ANS-saturated and unsaturated What differs saturated from unsaturated fatty acids? - ANS-Unsaturated fatty acids have double bonds; a monounsaturated having one, whereas a polyunsaturated having multiple What are cis and trans isomers? - ANS-cis having the double bond elements on the same side, trans on opposite Benefit of lipids over carbohydrates? - ANS-Lipids have a higher energy content and can act as thermal insulators What is the primary protein structure? - ANS-the number and sequence of amino acids in a polypeptide What is the secondary protein structure? - ANS-Beta pleated sheet and alpha helix. Hydrogen bonds between polypeptides form these structures
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? - ANS-38 total 2 in glycolysis 2 in Krebs's cycle 34 in chemiosmosis (electron transport chain) What is DNA replication? - ANS-the process of copying DNA What is DNA transcription? - ANS-the organic process whereby the DNA sequence in a gene is copied into mRNA What is translation? - ANS-the decoding of an mRNA message into amino acids which ultimately form protein what are the stages of transcription? - ANS-Initiation, elongation, termination How does DNA replication occur? - ANS- what is the nucleus - ANS-A part of the cell containing DNA and RNA and responsible for growth and reproduction What are chromosomes? - ANS-Chromosomes are long, thin strings composed of DNA and proteins which carry genes. What is the function of the endoplasmic reticulum? - ANS-Modifies, packages, and transports proteins What is the function of the golgi apparatus? - ANS-sorts and modifies proteins that have arrived from the rough ER What is the function of ribosomes? - ANS-protein synthesis by translating mRNA What is the cytoskeleton? - ANS-a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence. What is exocytosis? - ANS-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? - ANS-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? - ANS-The cell membrane regulates what enters and leaves the cell and also protects and supports the cell
Cell membrane diagram - ANS- Describe the process of mitosis - ANS-- 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 - ANS-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? - ANS-prophase I of meiosis When does recombination occur in meiosis? - ANS-during prophase I, when homologous chromosomes line up in pairs and swap segments of DNA. What is the structure of prokaryotic cells? - ANS- Example of prokaryotic cell - ANS-E. coli Example of eukaryotic cell - ANS-plant and animal cells What is the structure of eukaryotic cells? - ANS- What is the structure of a virus? - ANS-A typical virus is composed of a core of DNA or RNA surrounded by a protein coat What is transformation? - ANS-uptake of DNA from environment What is conjugation? - ANS-A process in which 2 organisms exchange genetic material What are all the parts to the digestive system? - ANS- How does absorption occur? - ANS-diffusion, facilitated diffusion, osmosis, active transport
Second line: Inflammation Third line: Adaptive (acquired) immunity How does blood clotting occur? - ANS-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 is innate immunity? - ANS-Nonspecific protection against foreign substances indiscriminantly All cells but lymphocytes What is the humoral immune response? - ANS-The humoral immune response targets pathogens circulating in "humors," or extracellular fluids, such as blood and lymph. Antibodies target invading pathogens for destruction via multiple defense mechanisms, including neutralization, opsonization, and activation of the complement system. Patients that are impaired in the production of antibodies suffer from severe and frequent infections by common pathogens and unusual pathogens What are muscles? - ANS-tissues or fibers that cause movement of body parts and organs Structure of muscles - ANS-each muscle fiber contains many microfibrils each divided along its length into repeating units called sacromeres General definition of joints - ANS-Areas where two or more bones join together Describe muscle contraction - ANS-Muscle contraction Is caused by interactions of thick and thin filaments Thin filament (actin) is attached to Z line Thick filaments (myosin) is "hanging" in the middle When myosin attaches to actin it pulls strings of actin toward each other Parts of the male reproductive system - ANS- Parts of the female reproductive system - ANS-
Describe the ovarian cycle - ANS-Eggs are formed through meiosis in ovaries 1 matures enough to be released into fallopian tubes (halfway through monthly cycle) Corpus luteum where egg used to be disintegrates unless fertilized What causes ovulation? - ANS-surge of LH What causes menstruation? - ANS-drop in estrogen and progesterone What are the pituitary gland hormones and what are their functions? - ANS-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? - ANS-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? - ANS-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 - ANS-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? - ANS-simple pathways in the nervous system that rapidly generate muscle contractions Explain the functions of the spinal cord - ANS-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? - ANS-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 - ANS-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
What is turner syndrome caused by? - ANS-45 chromosomes instead of 46 What is Klinefelter syndrome caused by? - ANS-47 chromosomes, three sex chromosomes, XXY What is edward's syndrome caused by? - ANS-Trisomy 18 What is Patau syndrome caused by? - ANS-Trisomy 13 What is dominant inheritance? - ANS-one dominant allele is needed to show disease and dominant lethal alleles are usually eliminated from the population What is recessive inheritance? - ANS-Inheritance of a trait that must be inherited homozygously in order for there to be a phenotype. What is sex-linked inheritance? - ANS-An inheritance pattern in which the gene of interest is carried on the X chromosome What are some common sex-linked diseases? - ANS-hemophilia (male - X linked recessive), red-green color blindness (male), congenital night blindness (male) What is the genetic code? - ANS-collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis summary of lac operon - ANS-The lac operon is an operon, or group of genes with a single promoter (transcribed as a single mRNA). The genes in the operon encode proteins that allow the bacteria to use lactose as an energy source What is Darwin's theory? - ANS-Natural selection and variation What is the parasympathetic nervous system's effect on a pacemaker? - ANS- Parasympathetic Stimulation Slows the Heart Rate by Decreasing the Slope of the Pacemaker Potential What bones are in the appendicular skeleton? - ANS-Upper Extremities
- Shoulder (pectorial) girdle
- Arm
- Wrist
- Hands Lower Extremities
- Hip (pelvic) girdle
- Legs
- Ankles
- Feet
What type of hormones enter their target cells? - ANS-Being lipids, steroid hormones enter the cell by simple diffusion across the plasma membrane What type of muscle is the diaphragm? - ANS-skeletal muscle Which vitamins are soluble in water? - ANS-B and C What is pepsin? - ANS-Enzyme that breaks down proteins in the stomach What is pepsin made of? - ANS-short polypeptides linked together What is tubulin? - ANS-Hollow tubes 25 nanometers in diameter What are centrioles? - ANS-Centrioles help organize cell division and are formed from tubulin and located near the nucleus. What is triploidy? - ANS-three sets of chromosomes What is monoploidy? - ANS-missing a chromosome in a set of chromosomes What is aneuploidy? - ANS-Abnormal number of chromosomes What is a gonosome? - ANS-synonym for sex chromosome What is autosomal? - ANS-chromosomes that are not sex chromosomes What is connective tissue? - ANS-Framework of the body, providing support and structure for the organs. What is included in connective tissue? - ANS-Loose ordinary connective tissue Adipose tissue Blood and blood forming tissues Dense ordinary connective tissue Cartilage Bone What is the epithelium? - ANS-A tissue that lines internal and external tissues in animals.
