BPK 105 MIDTERM EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026

BPK 105 MIDTERM EXAM QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026 Anatomy - Answers -investigates the structure of the body -relationship between the structure of a body part and it's function -can be systemic or regional Physiology - Answers -deals with the process or functions of living things Goals: (1) to understand and foreshadow the body's natural responses to changes (2) understand how the body controls and maintains their conditions Organ Systems - Answers -group of organs that is classified as a unit due to their similar function -Muscular, Nervous, Endocrine, Cardiovascular, Lymphatic, Respiratory, Digestive, and Urinary Systems 6 Characteristics of Life - Answers 1) Organization 2) Metabolism 3) Responsiveness 4) Growth 5) Development 6) Reproduction Homeostasis - Answers Existence and maintenance of a relatively constant environment within the body despite fluctuations in the external/internal environment; includes temperature, volume and chemical content Negative Feedback - Answers Deviation from the set point is made smaller or is resisted; maintains variation within a normal range without preventing it. Maintains homeostasis Three Components: -Receptor -Control Centre -Effector Ionic Bonds - Answers Transfer of electrons between atoms; creates oppositely charged ions Polar Covalent Bonds - Answers Electrons are unequally shared between two atoms; results in a slightly positive charge on one side of the molecule and a slightly negative charge on the other side Nonpolar Covalent Bonds - Answers Equal sharing of electrons between two atoms; has an even distribution of charges among the molecule Hydrogen Bonds - Answers Positive end of a polar molecule is attracted to the negative end of another polar molecule, and vice versa; not a chemical bond and is weaker than ionic/covalent bonds Compound - Answers Substance resulting from the chemical combination of 2+ different types of atoms Dissociation - Answers -Process of ionic compounds dissolving in water causing their ions to separate from each other -Positively charged ions are attracted to the negative ends of the water molecule and vice versa -Dissociated ions are called electrolytes Synthesis - Answers -Anabolism -Two or more reactants combine to form a larger and more complex product Decomposition - Answers -Catabolism -Reactants are broken down into smaller, and less complex products Exchange reactions - Answers -Reactants are decomposed then resynthesized with its counterparts Factors That Affect the Rate of Chemical Rxn - Answers 1. Reactants 2. Concentration 3. Temperature 4. Catalysts pH Scale - Answers Indicates the H+ concentration of a solution Acidity - Answers Greater concentration of H+ greater than OH-, has a pH less than 7.0 Basic/Alkaline - Answers Concentration of OH- greater than H+, has a pH greater than 7.0 Buffer - Answers A chemical used to resist the changes in pH when an acid or a base is added to a solution that has the buffer in it; binds to the H+/OH- preventing the ions from causing a shift in the pH Reversible Reaction - Answers A chemical reaction that can proceed from reactants to products and from products to reactants Equilibrium - Answers The state in which a chemical reaction's rate of product formation is equal to the rate of reactant formation 4 Properties of H2O - Answers 1) Stabilizing Body Temperature 2) Protection 3) Facilitating Chemical Reactions 4) Transporting Substances Carbohydrates - Answers -Consist of monosaccharides -Can be stored and broken down and used as an energy source -2:1 ratio of H to O for each C atom Monosaccharides - Answers Building block of carbs; forms longer chains of carbs Disaccharides - Answers -2 sugars - 2 monosaccharides are joined by a covalent bond Polysaccharides - Answers -Many monosaccharides bound in long chains -Glycogen, cellulose Lipids - Answers -Consists of glycerol and fatty acids; hydroxyl and carboxyl groups -Only dissolves in nonpolar solvents -Organic; composes of phosphorus and nitrogen -Stores energy Triglycerides - Answers Most common type of fat molecule Saturated Fatty Acids - Answers Contains only single covalent bonds between carbon atoms Unsaturated Fatty Acids - Answers Has 1+ double covalent bonds -Monosaturated -Polyunsaturated Trans Fatty Acids - Answers Unsaturated fats that have been chemically altered by the addition of H atoms Phospholipids - Answers -Component of cell structure and membrane -Hounded to a phosphorus containing molecule instead of glycerol -Has a hydrophobic and hydrophilic end Eicosanoids - Answers regulatory molecules Denaturation - Answers Broken hydrogen bonds in the protein; cannot maintain shape Enzymes - Answers Protein catalyst; increases the rate of chemical rxn by lowering the activation energy lock-and-key model - Answers Can quickly join amino acids to synthesis a protein; after the reaction is finished the enzyme is released and can be used again. Facts that Affect Rate of Chemical Rxn - Answers 1) Different reactants have different abilities 2) greater the concentration of the reactant, the greater the rate 3) Environmental temperature effects molecular motion Nucleic Acids - Answers -Has phosphorus and nitrogen -Transferred from one generation of cells to the next -Are made up from a series of nucleotides; is an organic molecule -Has hydrogen bonds Proteins - Answers -Has oxygen and sulfur -Obtainable from food -Made from amino acids and bonded by H2 bonds -Consists of an amine group and a carboxyl group -Macronutrient -Function depends on the protein molecule's structure Nucleotides - Answers Building block of nucleic acids; composed of a monosaccharide with a nitrogenous organic base and a phosphate group are attached Deoxyribonucleic Acid (DNA) - Answers -Genetic material of cells; copied from one generation of cells to the next -Determines the structure of proteins -Defines all cellular activities, such as the rate and type of chemical reactions that occur in the cell Ribonucleic Acid (RNA) - Answers Plays a role in gene expression or protein synthesis; similar to DNA Cell Membrane - Answers Outermost component of cell; encloses the cytoplasm. Composed of phospholipids, proteins and other traces of carbs and cholesterol Nucleus - Answers -Contains DNA and nucleoli -Site of RNA synthesis and ribosomal subunit assembly Ribosomes - Answers Where proteins are produced; can be free ribosomes and roam Rough ER - Answers Ribosomes attach themselves to here Smooth ER - Answers Synthesizes lipids; detoxifies Golgi Apparatus - Answers Modifies and packages proteins in secretory vesicles; produces lysosomes Secretory Vesicles - Answers Contains the material produced in the cell; secreted via exocytosis -Formed by golgi apparatus Lysosome - Answers Contains enzymes that digest material taken into the cell Mitochondrion - Answers Synthesizes ATP; site of aerobic respiration Microtubles - Answers Structurally supports the cytoplasm; forms components of the cilia and flagella. Assists in cell division Centriole - Answers Facilitates the movement of chromosomes during cell division Cilia - Answers Moves substances over the cell's surfaces Flagella - Answers Propels sperm cell, on cell of surface Microvilli - Answers Increases surface area of certain cells; extensions of the cell surface Nuclear Envelope - Answers Bounds the nucleus, consists of outer and inner membranes with a narrow space between them Nuclear Pores - Answers Point where the inner and outer membrane come together to form a hole Nucleolus - Answers Found in the nucleus; produces rRNA acid to form large and small ribosomal subunits Diffusion - Answers solute moves from an area of higher concentration to an area of lower concentration Phospholipid Bilayer - Answers Acts as a barrier to most water-soluble substances and allows lipid-soluble molecules to pass by -Has channels that allow certain substances to pass depending on their size, shape and charge -Leak and Gated Osmosis - Answers Diffusion of H2O from a region of higher water concentration to one of lower water concentration; controls the large volume changes caused by water movement Osmotic Pressure - Answers -Force required to prevent the movement of water across a selectively permeable membrane -Greater the concentration of a solution, the greater its osmotic pressure Carrier Mediated Transport - Answers -Move large, water-soluble molecules or electrically charged ions across the cell membrane -Facilitated diffusion, active transport, and secondary active transport Endocytosis - Answers -Uptake of material through the cell membrane by the formation of a vesicle -Cell membrane folds inwards to form a vesicle containing the material to be taken into the cell and is then moved into the cytoplasm -receptor-mediated endocytosis; Phagocytosis and Pinoycytosis Phagocytosis - Answers Ingestion of solid particles; requires ATP Pinocytosis - Answers -Contains liquids -Are in much smaller vesicles; requires ATP to be formed Exocytosis - Answers Membrane of the vesicle fuses with the cell membrane to eliminate the material inside from the cell; ATP is needed to form the vesicle Facilitated Diffusion - Answers Goes from an area of higher concentration to an area of lower concentration; does not requires ATP since movement is with the concentration gradient Active Transport - Answers Moves substances across the cell membrane from regions of lower concentration to those of higher concentration against a concentration gradient; requires ATP Secondary Active Transport - Answers Involves the active transport of one substance across the cell membrane establishing a concentration gradient; provides enough energy to transport a second substance; can cotransport or countertransport Selective Permeability - Answers Phospholipid bilayer cellular membranes that only allows certain molecules to enter or exit the cell -Outer surface: hydrophilic polar heads -Inner surface: hydrophobic nonpolar tails consisting of fatty acid chains Hypotonic Solution - Answers -Has less solute and a higher concentration of water relative to the cytoplasm of the cell -Results in lysis Isotonic Solution - Answers concentration of solute == concentration solvent; equilibrium Hypertonic Solution - Answers -Has a higher concentration of solutes and a lower concentration of water relative to the cytoplasm -Results in crenation Gene Expression - Answers -Process of transcription and translation of a gene; takes place in the nucleus of the cell -Determines the structure of the mRNA The double strands of a DNA segment separate and DNA nucleotides pair with RNA nucleotides. The number and sequence of a nucleotide in the DNA serves as a template to produce the number and sequence of nucleotides in the mRNA. DNA nucleotides pair with other specific RNA nucleotide's organic bases according to the base-pair combinations, with the aid of an enzyme. As the nucleotides are added, an mRNA molecule is formed. Codon - Answers information in mRNA is carried in groups of 3 nucleotides and specifies a particular amino acid Translation - Answers -Second step of gene expression; takes place in the ribosomes -synthesis of proteins based on the information in the mRNA happens small and large subunits from the ribosomes combine with the mRNA, and aligns the mRNA with tRNA molecules. Then, a series of 3 nucleotides of tRNA (anticodon) pairs with the codon of the mRNA. An amino acid is bound to another part of the tRNA and ensures that it is correctly matched with the codon of the mRNA. An enzyme from the ribosome then forms a peptide bond between the amino acids bounded to the tRNAs. The bonding the process continues and forms a polypeptide chain, and folds into a 3D structure of the protein molecule. Life Cycle of a Cell - Answers -Interphase -Cell division -Differentiation -Apoptosis Interphase - Answers non-dividing phase; cells spend most of its life cycle performing normal functions in interphase and replicating its DNA -DNA is dispersed throughout the nucleus as thin threads (Chromatin) Cell Division - Answers -Formation of daughter cells from a single parent cell -Mitosis, meiosis Mitosis - Answers Formation of new cells necessary for growth and tissue repair 1) Prophase 2) Metaphase 3) Anaphase 4) Telophase Apoptosis - Answers Excess cells, damaged cells or dangerous cells are eliminated to maintain a constant number of cells or to prevent regression within the tissue; programmed cell death Differentiation - Answers process occurs during cell division; differentiated by the selective activation and inactivation of different segments of DNA 4 Main Cell Functions - Answers 1) Cell Metabolism and Energy Use 2) Synthesis of Molecules 3) Communication 4) Reproduction and Inheritance sodium-potassium pump - Answers -moves sodium out of cells and potassium into the cells - there is a higher sodium concentration outside of the cell and a higher potassium concentration in the cell Concentration Gradient - Answers The difference in the concentration of a solute in a solvent between 2 points divided by the distance between the two points; is steeper when the concentration difference is large and/or the distance is small Functions of Skeletal Muscle - Answers -Movement -Posture -Body heat -Contractility, Excitability, Extensibility, Elasticity Functions of Smooth Muscle - Answers -Compresses organs, ducts, tubes -Constriction of organs and vessels Functions of Cardiac Muscle - Answers -Contractions of the heart to propel blood through the body Resting Membrane Potential - Answers Charge difference across the membrane of a resting cell; or a cell that has not been stimulated to produce and action potential -Concentration of K+ inside the cell membrane is higher than that outside the cell -Concentration of Na+ outside the cell membrane is higher than the inside of the cell -Cell membrane is more permeable to K+ than it is to Na+ Polarized Cell Membrane - Answers negatively charged outside and positively charged inside Action Potential - Answers Rapid change between depolarization and repolarization of the cell membrane; triggers muscle contractions Depolarization - Answers Makes the inside of the cell membrane positively charged; Na+ diffuses down its concentration gradient through the open Na+ channels Repolarization - Answers Makes the inside of the cell membrane negatively charged once again; movement of K+ going out Role of the Sodium-Potassium Exchange Pump - Answers -Results in an action potential/muscle contraction -Makes sure that an uneven distribution of K+ and Na+ is maintained across the cell membrane -Transport Na+ from the inside to outside the cell and K+ from outside to inside of the cell to maintain a negative charge inside the cell than out Functional Steps that Occur at the Neuromuscular Junction - Answers 1) During the stimulation of a motor neuron, the action potential will travel down the axon through a neuromuscular junction into the presynaptic terminals. 2) When an action potential reaches the presynaptic terminal, it causes Ca2+ channels to open and allows Ca2+ ions to enter. It causes several synaptic vesicles to enter and release acetylcholine into the synaptic cleft by exocytosis. 3) The acetylcholine diffuses across the synaptic cleft and binds to acetylcholine receptor sites on the Na+ channels in the muscle fibre cell membranes. 4) The acetylcholine and its receptor opens Na+ channels and makes the cell membrane more permeable to Na+. The movement of Na+ results in the muscle fibre initiating an action potential one the threshold is reached. 5) The action potential travels along the length of the muscle fiber and causes it to contract. To prevent more acetylcholine from binding to the receptor protein and a second action potential, the enzyme acetylcholinesterase breaks down the acetylcholine released into the synaptic cleft between the neuron and the muscle fiber. This ensures than one action potential in the neuron yields only one action potential in the skeletal muscle fibres of that motor unit and only one contraction. Sliding Filament Mode - Answers -Actin and myosin myofilaments slide over one another during muscle contraction -During contraction, neither the actin nor the myosin fibers shorten -H zones and I bands shorten during contraction, but the A bands do not change in length Relaxed Sarcomere - Answers -Actin and myosin myofilaments overlap slightly; makes H zone visible -During contraction, actin myofilaments slide past the myosin myofilaments bringing the Z disks closer together -H zone and I bands narrow, since the length of the myosin does not change Fully Contracted Sarcomere - Answers H zone completely disappears because the actin and myosin myofilaments overlap each other; I bands and Z disks become very narrow Cross Bridge Movement - Answers 1) An action potential travels along an axon membrane to a neuromuscular junction. 2) Ca2+ channels opens and Ca2+ ions enter the presynaptic terminal. 3) Acetylcholine is released from the presynaptic vesicles and stimulates the Na+ channels on the presynaptic membrane to open. 4) Na+ diffuses into the muscle fiber, initiating an action potential that travels along the sarcolemma and T Tubule membranes. 5) The action potentials in the T Tubules cause the sarcoplasmic reticulum to release Ca2+ 6) On the actin myofilament, the Ca2+ binds to troponin, which moves tropomyosin and exposes myosin attachment sites. 7) ATP molecules break down to ADP and P which releases energy needed to move the myosin heads. 8) The heads of the myosin myofilament bend, causing the actin to slide past the myosin. The cycle repeats as long as Ca2+ is present. Tetanus - Answers Sustained muscle contractions caused by a series of nerve stimuli repeated so rapidly that the individual contractions are fused together. No relaxation occurs. Phases of a Single Muscle Twitch - Answers 1) Lag phase 2) Contraction Phase 3) Relaxation Phase Aerobic Respiration - Answers -Occurs in the mitochondria -During most exercise and normal conditions; requires O2 -Decomposes glucose to make ATP, CO2, and H2O -Can use fatty aids and amino acids to produce ATP Anaerobic Respiration - Answers -Does not require O2 -Decomposes glucose to make lactic acid and ATP -Intensive short-term work Creatine Phosphate - Answers -Molecule that stores energy that can be used rapidly to maintain adequate levels of ATP -When resting, the excess ATP produced is used to synthesize creatine phosphate -ATP reserve is quickly depleted and is then broken down to directly synthesize ATP Characteristics of Smooth Muscle - Answers -Small and spindle-shaped -Not striated -Usually has one nucleus per cell -Contains less actin and myosin than skeletal muscle cells -Myofils are not organized into sarcomeres -Cells are organized to form layers and functions/contracts as a unit -Contract more slowly than muscle cells when stimulated by neurotransmitters -Is autorhythmic; has periodic spontaneous contractions -Under involuntary control; can be stimulated by hormones -Compresses organs, ducts, tubes Characteristics of Skeletal Muscle - Answers -Under involuntary control -Not autorhythmic -Long and cylindrical cell shape -Has many nuclei -Is striated Characteristics of Cardiac Muscle - Answers -Long, striated and branched muscle cells -Actin and myosin myofilaments are organized into sarcomeres; distribution of myofilaments is not as uniform -Contractions are autorhythmic -Connected to each other by intercalated disks -Under involuntary control Neuromuscular junction - Answers -Axon Branch -Presynaptic terminal -Synaptic terminal -Synaptic cleft -Postsynaptic membrane/Sarcolemma