ktp-mcat-quicksheets.pdf

 other Senses CognItIon, ConSCIouSnESS, AnD lAnguAgE Smell: detection of volatile or aerosolized chemicals by olfactory chemoreceptors Consciousness...

 other Senses CognItIon, ConSCIouSnESS, AnD lAnguAgE Smell: detection of volatile or aerosolized chemicals by olfactory chemoreceptors Consciousness Piaget’s Stages of Cognitive Development (olfactory nerves) Sensorimotor stage: focuses on manipulating Stage EEg Waves features taste: detection of dissolved compounds by the environment to meet physical needs taste buds in papillae Awake Beta and Able to perceive, process, through circular reactions; object permanence Somatosensation: four touch modalities alpha access, and express ends this stage (pressure, vibration, pain, and temperature) information Preoperational stage: focuses on symbolic kinesthetic sense (proprioception): ability to 1 Theta Light sleep thinking, egocentrism (inability to imagine tell where one’s body is in space what another person thinks or feels), and 2 Theta Sleep spindles and K centration (focusing on only one aspect of a complexes phenomenon) object recognition 3/4 Delta Slow-wave sleep; dreams; Concrete operational stage: focuses on Bottom-up (data-driven) processing: recognition understanding the feelings of others and declarative memory of objects by parallel processing and feature manipulating physical (concrete) objects consolidation; some sleep detection. Slower, but less prone to mistakes disorders formal operational stage: focuses on abstract top-down (conceptually-driven) processing: thought and problem-solving recognition of an object by memories and rEM Mostly Appears awake expectations, with little attention to detail. beta physiologically; dreams; paralyzed; procedural Problem-Solving and Decision-Making Faster, but more prone to mistakes gestalt principles: ways that the brain can memory consolidation; some Problem-solving techniques include trial-and- infer missing parts of an image when it is sleep disorders error, algorithms, deductive reasoning (deriving incomplete conclusions from general rules) and inductive Sleep disorders include dyssomnias (amount or reasoning (deriving generalizations from evidence). timing of sleep), such as insomnia, narcolepsy, sleep lEArnIng AnD MEMorY apnea, and sleep deprivation; and parasomnias Heuristics (simplified principles used to make (odd behaviors during sleep), such as night terrors decisions, “rules of thumb”), biases, intuition, and learning and sleepwalking (somnambulism). emotions may assist decision-making, but may also lead to erroneous or problematic decisions. habituation: the process of becoming used to a stimulus Consciousness-Altering Drugs Dishabituation: occurs when a second Drug addiction is mediated by the mesolimbic Attention stimulus intervenes, causing a resensitization pathway, which includes the nucleus accumbens, Selective attention: allows one to pay to the original stimulus medial forebrain bundle, and ventral tegmental area. attention to a particular stimulus while observational learning: the acquisition of Dopamine is the main neurotransmitter. determining if additional stimuli require behavior by watching others attention in the background Associative learning: pairing together Drug group function Divided attention: uses automatic processing to stimuli and responses, or behaviors and Depressants Sense of relaxation pay attention to multiple activities at one time consequences (alcohol, barbiturates, and reduced anxiety Classical conditioning: a form of associative benzodiazepines) language Areas in the Brain learning in which a neutral stimulus becomes Wernicke’s area: language comprehension; Stimulants Increased arousal associated with an unconditioned stimulus damage results in Wernicke’s aphasia (amphetamines, cocaine, such that the neutral stimulus alone produces (fluent, nonsensical aphasia with lack of ecstasy) the same response as the unconditioned comprehension) stimulus; the neutral stimulus thus becomes a opiates/opioids Decreased reaction to Broca’s area: motor function of speech; conditioned stimulus (heroin, morphine, pain; euphoria damage results in Broca’s aphasia (nonfluent opium, pain pills) aphasia in which generating each word hallucinogens Distortions of requires great effort) + (LSD, peyote, mescaline, reality and fantasy; Arcuate fasciculus: connects Wernicke’s UCS (food) Neutral ketamine, psilocybin- introspection and Broca’s areas; damage results in stimulus UCR (bell) No Response containing mushrooms) conduction aphasia (the inability to repeat words despite intact speech generation and Marijuana has some features of depressants, comprehension) stimulants, and hallucinogens (in very high doses). Memory MotIvAtIon, EMotIon, AnD StrESS Human Memory CS (bell) Motivation Sensory Short-term Working Long-term CR (salivation) Memory Memory Memory Memory Motivation is the purpose or driving force behind (< 1 sec) (< 1 min) (lifetime) our actions. operant conditioning: a form of associative Extrinsic: based on external circumstances learning in which the frequency of a behavior Explicit Implicit Intrinsic: based on internal drive or perception is modified using reinforcement (increases Memory Memory behavior) or punishment (decreases behavior) (conscious) (unconscious) Motivation theories Stimulus Instinct theory: innate, fixed patterns of Declarative Procedural Added Removed Memory Memory behavior in response to stimuli (facts, events) (skills, tasks) Arousal theory: the state of being awake and Continues reactive to stimuli; aim for optimal level of Positive Negative arousal for a given task (Yerkes–Dodson law) Episodic Semantic reinforcement reinforcement Memory Memory Strong Optimal arousal (events, experiences) (facts, concepts) Behavior Optimal performance Encoding: the process of putting new Performance Impaired performance information into memory because of strong anxiety Facts are stored via semantic networks. retrieval Stops Positive Negative punishment punishment of information is often based on priming Increasing attention interconnected nodes of the semantic network. Weak and interest recognition of information is stronger than recall. Low High Arousal 01_MCAT_QS_BehavSci.indd 2 4/10/14 12:03 PM  Drive reduction theory: individuals act to PSYChologICAl DISorDErS relieve internal states of tension Maslow’s hierarchy of needs: prioritizes needs Diagnostic and Statistical Manual of Mental Disorders Anxiety disorders into five categories: physiological needs (DSM): the guide by which most psychological disorders generalized anxiety disorder: constant (highest priority), safety and security, love and are characterized, described, and diagnosed. disproportionate and persistent worry belonging, self-esteem, and self-actualization Specific phobias: irrational fears of specific types of Psychological Disorders objects (lowest priority) Schizophrenia: psychotic disorder characterized by Social anxiety disorder: anxiety due to social distortions of reality and disturbances in content or performance situations Emotion and form of thought, perception, and behavior. Agoraphobia: fear of places or situations Seven universal emotions: happiness, sadness, Positive symptoms include hallucinations, delusions, where it is hard for an individual to escape contempt, surprise, fear, disgust, anger and disorganized thought and behavior. negative Panic disorder: recurrent attacks of intense, theories of emotion: symptoms include disturbance of affect and avolition. overwhelming fear and sympathetic nervous Depressive disorders system activity with no clear stimulus. It may first Second lead to agoraphobia. theory response response Major depressive disorder: contains at least one major depressive episode obsessive–compulsive disorder: obsessions James–lange Nervous Conscious Pervasive depressive disorder: a depressed (persistent, intrusive thoughts and impulses) and system emotion mood (either dysthymia or major depression) compulsions (repetitive tasks that relieve tension but arousal for at least two years cause significant impairment) Cannon–Bard Nervous Action Seasonal affective disorder: the colloquial Body dysmorphic disorder: unrealistic negative StIMuluS system name for major depressive disorder with evaluation of one’s appearance or a specific body part arousal and seasonal onset, with depression occurring conscious during winter months Dissociative disorders emotion Dissociative amnesia: inability to recall past Schachter–Singer Nervous Conscious Bipolar and related disorders experience. May involve dissociative fugue, a system emotion Bipolar I disorder: contains at least one manic sudden change in location that can involve the arousal and episode assumption of a new identity cognitive Bipolar II disorder: contains at least one Dissociative identity disorder: two or more appraisal hypomanic episode and at least one major personalities that take control of behavior depressive episode Depersonalization/derealization disorder: Cyclothymic disorder: contains hypomanic feelings of detachment from the mind and Stress episodes with dysthymia body, or from the environment Stress: the physiological and cognitive response to challenges or life changes formation of Identity Personality Primary appraisal: classifying a potential freud’s stages of psychosexual development Psychoanalytic perspective: personality results from stressor as irrelevant, benign–positive, or Based on tensions caused by the libido, with unconscious urges and desires stressful failure at any given stage leading to fixation Freud: id, superego, ego Secondary appraisal: directed at evaluating Jung: collective unconscious, archetypes whether the organism can cope with the humanistic perspective: emphasizes internal stress, based on harm, threat, and challenge feelings of healthy individuals as they strive toward Conscious Stressor (distress or eustress): anything that leads happiness and self-realization to a stress response; can include environmental, Maslow: hierarchy of needs social, psychological, chemical, and biological Rogers: unconditional positive regard stressors Preconscious type and trait theory: personality can be described The three stages of the general adaptation syndrome ego as a number of identifiable traits that carry are alarm, resistance, and exhaustion. superego characteristic behaviors good health bad stress id Type theories of personality: ancient Greek 1. Alarm 3. Exhaustion humors, Sheldon’s somatotypes, division into Good health stage Unconscious stage types A and B, and the Myers–Briggs type Resistance panic zone (homeostasis) 2. Resistance Inventory stage Eysenck’s three major traits: psychoticism, breakdown (burnout) extraversion, neuroticism Time Trait theorists’ Big Five: openness, Erikson’s stages of psychosocial development conscientiousness, extraversion, agreeableness, and neuroticism (OCEAN) IDEntItY AnD PErSonAlItY Stem from conflicts that are the result of decisions we are forced to make about ourselves and the Allport’s three basic types of traits: cardinal, Self-Concept and Identity environment around us at each phase of our lives central, and secondary Self-concept: the sum of the ways in which Stages are trust vs. mistrust, autonomy vs. we describe ourselves: in the present, who we shame and doubt, initiative vs. guilt, industry used to be, and who we might be in the future vs. inferiority, identity vs. role confusion, Identities: individual components of our self- intimacy vs. isolation, generativity vs. concept related to the groups to which we belong stagnation, integrity vs. despair Self-esteem: our evaluation of ourselves kohlberg’s theory of moral reasoning development Self-efficacy: the degree to which we see Describes the approaches of individuals to ourselves as being capable of a given skill in a resolving moral dilemmas given situation Six stages are divided into three main locus of control: a self-evaluation that refers phases: preconventional, conventional, and to the way we characterize the influences in postconventional our lives. Either internal (success or failure is a result of our own actions) or external (success vygotsky’s theory of cultural and biosocial or failure is a result of outside factors) development Describes development of language, culture, and skills 01_MCAT_QS_BehavSci.indd 3 4/10/14 12:03 PM  Somatic symptom and related disorders social interaction Cultural relativism: studying social groups and Somatic symptom disorder: at least one cultures on their own terms somatic symptom, which may or may not be Elements of Social Interaction Discrimination: when prejudicial attitudes linked to an underlying medical condition, that Status: a position in society used to classify cause differences in treatment of a group causes disproportionate concern individuals. Can be ascribed (involuntarily Illness anxiety disorder: preoccupation with assigned), achieved (voluntarily earned), or social structure and demographics having or coming down with a serious medical master (primary identity) condition Role: set of beliefs, values, and norms that Conversion disorder: unexplained symptoms define the expectations of a certain status Sociology: Theories and Institutions affecting motor or sensory function Group: two or more individuals with similar Functionalism: focuses on the function and characteristics who share a sense of unity relationships of each component of society Personality disorders Network: observable pattern of social Conflict theory: focuses on how power Patterns of inflexible, maladaptive behavior that relationships between individuals or groups differentials are created and how they cause distress or impaired functioning Organization: group with a structure maintain order Cluster A (odd, eccentric, “weird”): paranoid, and culture designed to achieve specific Symbolic interactionism: the study of schizotypal, schizoid goals; exists outside of each individual’s how individuals interact through a shared membership within the organization understanding of words, gestures, and other Cluster B (dramatic, emotional, erratic, “wild”): symbols antisocial, borderline, histrionic, narcissistic Self-Presentation and Interacting with Others Social constructionism: explores how Cluster C (anxious, fearful, “worried”): individuals and groups make decisions to avoidant, dependent, obsessive–compulsive Display rules: unspoken rules that govern the agree upon a given social reality expression of emotion social processes, attitudes, Impression management: maintenance of a Culture and behavior public image through various strategies Dramaturgical approach: individuals create Material culture: physical items one Group Psychology images of themselves in the same way that associates with a given group (art, clothing, actors perform a role in front of an audience foods, buildings) Social facilitation: tendency to perform at a different level (better or worse) when others Symbolic culture: the ideas associated with a are around social thinking cultural group Deindividuation: loss of self-awareness in Social Behavior Demographics large groups; can lead to drastic changes in behavior Interpersonal attraction: influenced by Demographics: the statistical arm of sociology Bystander effect: in a group, individuals are physical, social, and psychological factors Migration refers to the movement of people into less likely to respond to a person in need Aggression: behavior with the intention to (immigration) or out of (emigration) a geographical Peer pressure: social influence placed on an cause harm or increase social dominance location. individual by other individuals they consider Attachment: an emotional bond to another Demographic transition: a model used to represent equals person; usually refers to the bond between a drops in birth and death rates as a result of Group polarization: tendency towards making child and a caregiver industrialization decisions in a group that are more extreme then Altruism: helping behavior in which the the thoughts of the individual group members person’s intent is to benefit someone else at a Groupthink: tendency to make decisions personal cost based on ideas and solutions that arise within social stratification the group without considering outside ideas Social Perception and Behavior Social Class Culture Attribution Theory Social stratification is based on socioeconomic Assimilation: one culture begins to melt into Focuses on the tendency for individuals to infer the status (SES). another causes of other people’s behavior Class: a category of people with shared Multiculturalism: encouragement of multiple Dispositional (internal) causes relate to the socioeconomic characteristics cultures within a community to enhance features of the person who is being considered Power: the capacity to influence people diversity Situational (external) causes relate to features through real or perceived rewards and Subculture: a group that distinguishes itself of the surroundings or social context punishments from the primary culture to which it belongs Correspondent inference theory: describes Social capital: the investment people make attributions made by observing the intentional in society in return for economic or collective Socialization (especially unexpected) behaviors performed rewards Socialization: the process of developing and by another person Social reproduction: the passing on of spreading norms, customs, and beliefs Fundamental attribution error: bias toward social inequality, especially poverty, to other Norms: boundaries of acceptable behavior making dispositional attributions rather than generations within society situational attributions Poverty: low SES; in the US, the poverty line is Stigma: extreme disapproval or dislike the government’s calculation of the minimum of a person or group based on perceived Stereotypes, Prejudice, and Discrimination income requirements to acquire the minimum differences Stereotypes: attitudes and impressions that necessities of life Deviance: any violation of norms, rules, or are made based on limited and superficial expectations within a society information Epidemiology Self-fulfilling prophecy: the phenomenon new cases Conformity: changing beliefs or behaviors in Incidence: per time order to fit into a group or society of a stereotype creating an expectation of a population - at risk Compliance: individuals change behavior particular group, which creates conditions that based on the request of others; techniques lead to confirmation of this stereotype number of cases(new or old) for gaining compliance include foot-in-the- Stereotype threat: a feeling of anxiety about Prevalence: per time door, door-in-the-face, lowball, and that’s- confirming a negative stereotype total population not-all Prejudice: an irrationally based attitude prior Morbidity: the burden or degree of illness associated Obedience: change in behavior based on a to actual experience with a given disease command from someone seen as an authority Ethnocentrism: the practice of making Mortality: deaths caused by a given disease figure judgments about other cultures based on the values and beliefs of one’s own culture (in-group vs. out-group) 01_MCAT_QS_BehavSci.indd 4 4/10/14 12:03 PM  CARBOHYDRATE STRUCTURE DNA AND BIOTECHNOLOGY AND FUNCTION NH2 Centromeres are located in the middle of Carbohydrate Classification chromosomes and hold sister chromatids together Carbohydrates are organized by their number of N until they are separated during anaphase in mitosis. carbon atoms and functional groups. high-energy N They also contain a high GC-content. bonds 3-carbon sugars are trioses, 4-carbon sugars DNA Replication are tetroses, and so on. N N Sugars with aldehydes as their most oxidized O O O Step in Prokaryotic Eukaryotic group are aldoses; sugars with ketones as Replication Cells Cells (Nuclei) –O P O P O P O their most oxidized group are ketoses. CH2 O Origin of One per Multiple per Sugars with the highest-numbered chiral carbon with – – – O O O replication chromosome chromosome the –OH group on the right (in a Fischer projection) are D-sugars; those with the –OH on the left are Unwinding of Helicase Helicase L-sugars. D- and L-forms of the same sugar are OH OH DNA double enantiomers. ATP helix Diastereomers differ at at least one—but not all—chiral Stabilization Single- Single- carbons. Also include: DNA Structure of unwound stranded stranded template DNA-binding DNA-binding Epimers differ at exactly one chiral carbon. Nucleosides contain a five-carbon sugar bound to a strands protein protein Anomers are a subtype of epimers that differ nitrogenous base; nucleotides are nucleosides with at the anomeric carbon. one to three phosphate groups added. Synthesis of Primase Primase Nucleotides in DNA contain deoxyribose; in RNA, they RNA primers Cyclic Sugar Molecules contain ribose. Synthesis of DNA DNA Cyclization describes the ring formation of Nucleotides are abbreviated by letter: adenine (A), DNA polymerase III polymerases α carbohydrates from their straight-chain forms. cytosine (C), guanine (G), thymine (T), and uracil (U). and δ When rings form, the anomeric carbon can take on Removal of RNA DNA RNase H either an α- or β-conformation. Watson–Crick Model primers polymerase I (5'→3' The anomeric carbon is the new chiral center formed The DNA backbone is composed of alternating (5'→3' exonuclease) in ring closure; it was the carbon containing the sugar and phosphate groups, and is always exonuclease) carbonyl in the straight-chain form. read 5' to 3'. Replacement of DNA DNA α-anomers have the –OH on the anomeric There are two strands with antiparallel polarity, RNA with DNA polymerase I polymerase δ carbon trans to the free –CH2OH group. wound into a double helix. Joining of DNA ligase DNA ligase β-anomers have the –OH on the anomeric Purines (A and G) always pair with pyrimidines Okazaki carbon cis to the free –CH2OH group. (C, U, and T). In DNA, A pairs with T (via two fragments During mutarotation, one anomeric form shifts hydrogen bonds) and C pairs with G (via three hydrogen bonds). In RNA, A pairs with U (via Removal DNA DNA to another, with the straight-chain form as an two hydrogen bonds). of positive topoisomerase topoisomerase intermediate. Chargaff’s rules: purines and pyrimidines supercoils II (DNA gyrase) II (DNA gyrase) are equal in number in a DNA molecule. The ahead of Monosaccharides advancing amount of A equals the amount of T, and the CH2OH CHO CHO CHO amount of C equals the amount of G. replication C O H OH H OH HO H DNA strands can be pulled apart (denatured) and forks HO H HO H HO H HO H H OH H OH HO H H OH brought back together (reannealed). Synthesis of Not applicable Telomerase H OH H OH H OH H OH telomeres CH2OH CH2OH CH2OH CH2OH Eukaryotic Chromosome Organization D-fructose D-glucose D-galactose D-mannose DNA replication is semiconservative: one old parent DNA is organized into 46 chromosomes in human cells. strand and one new daughter strand is incorporated Monosaccharides are single carbohydrate units In eukaryotes, DNA is wound around histone proteins into each of the two new DNA molecules. and can undergo three main reactions: oxidation– (H2A, H2B, H3, and H4) to form nucleosomes, which leading strand DNA polymerase III reduction, esterification, and glycoside formation. may be stabilized by another histone protein (H1). 5’ on leading strand 3’ Glycoside formation is the basis for building complex DNA and its associated histones make up chromatin ssDNA-binding protein carbohydrates and requires the anomeric carbon to in the nucleus. leading strand template parent DNA helicase 3’ link to another sugar. DNA polymerase III Heterochromatin is dense, transcriptionally on lagging strand Okazaki fragment 5’ Sugars with a –H replacing an –OH group are termed silent DNA. primase 5’ deoxy sugars. Euchromatin is less dense, transcriptionally 5’ active DNA. lagging strand template Disaccharides with H1 without H1 DNA polymerase synthesizes new DNA strands, Common disaccharides include sucrose (glucose-α- 10 nm reading the template DNA 3' to 5' and synthesizing 30 nm 1,2-fructose), lactose (galactose-β-1,4-glucose), and the new strand 5' to 3'. maltose (glucose-α-1,4-glucose). The leading strand requires only one primer and can then be synthesized continuously. Polysaccharides The lagging strand requires many primers H2A Cellulose: main structural component of plant H2B H3 and is synthesized in discrete sections called cell walls; main source of fiber in the human H4 H1 H2A Okazaki fragments. expanded view of diet H3 H2B a nucleosome Starches (amylose and amylopectin): main expanded view H4 Recombinant DNA and Biotechnology energy storage forms for plants Recombinant DNA is DNA composed of nucleotides Glycogen: a major energy storage form for from two different sources. Telomeres are the ends of chromosomes. They animals contain a high GC-content to prevent unraveling of DNA cloning introduces a fragment of DNA into a the DNA. vector plasmid. A restriction enzyme (restriction endonuclease) cuts both the plasmid and the fragment, leaving them with sticky ends, which can bind. 02_MCAT_QS_Biochem.indd 6 4/10/14 12:02 PM  Once replicated, the bacterial cells can be used to Transcription BIOLOGICAL MEMBRANES create a protein of interest, or can be lysed to allow DNA transcription for isolation of the fragment of interest from the TATA box ATG TGA Membrane Transport vector. 5' –35 –10 coding region 3' Osmotic pressure, a colligative property, is the DNA libraries are large collections of known DNA 3' promoter 5' pressure applied to a pure solvent to prevent sequences. 5' untranslated region (UTR) 3' untranslated region (UTR) osmosis and is related to the concentration of Genomic libraries contain large fragments of +1 transcription the solution. transcription terminates DNA, including both coding and noncoding Π = iMRT mRNA GC-rich stem regions of the genome. They cannot be used Shine–Dalgarno AUG UGA and loop Passive transport does not require ATP because the coding region to make recombinant proteins or for gene sequence 5' UUUUUU 3' molecule is moving down its concentration gradient therapy. or from an area of higher concentration to an area of 5' UTR 3' UTR cDNA libraries (expression libraries) contain translation lower concentration. smaller fragments of DNA, and only include Simple diffusion does not require a the exons of genes expressed by the sample H2N–protein–COOH transporter. Small, nonpolar molecules tissue. They can be used to make recombinant Steps:Figure I-3-4. Expression of a Prokaryotic Protein Coding Gene passively move from an area of high proteins or for gene therapy. Helicase and topoisomerase unwind DNA concentration to an area of low concentration Hybridization is the joining of complementary base double helix. until equilibrium is achieved. pair sequences. Osmosis describes the diffusion of water RNA polymerase II binds to TATA box within Polymerase chain reaction (PCR) is an automated promoter region of gene (25 base pairs across a selectively permeable membrane. process by which millions of copies of a DNA upstream from first transcribed base). Facilitated diffusion uses transport proteins sequence can be created from a very small sample hnRNA synthesized from DNA template to move impermeable solutes across the cell by hybridization. (antisense) strand. membrane. DNA molecules can be separated by size using Posttranscriptional modifications: Active transport requires energy in the form of agarose gel electrophoresis. ATP (primary) or an existing favorable ion gradient 7-methylguanylate triphosphate cap added Southern blotting can be used to detect the (secondary). Secondary active transport can be to 5' end presence and quantity of various DNA strands in further classified as symport or antiport. Polyadenosyl (poly-A) tail added to 3' end a sample. After electrophoresis, the sample is Splicing done by spliceosome; introns transferred to a membrane that can be probed removed and exons ligated together. with single-stranded DNA molecules to look for a molecules Alternative splicing combines different exons transport sequence of interest. proteins to acquire different gene products. DNA sequencing uses dideoxyribonucleotides, which terminate the DNA chain because they lack a 3' –OH group. Translation { cell membrane Occurs at the ribosome. RNA AND THE GENETIC CODE concentration simple facilitated energy gradient diffusion diffusion (ATP or ion gradient) { Central Dogma: DNA → RNA → proteins A U G C C G U A U G C U A U G C C G U A U G C U U A C U A CG G C passive transport active transport The Genetic Code Endocytosis and exocytosis are methods of Figure 1.5 Movement Across Memberances Degenerate code allows multiple codons to encode Met P site A site Pro engulfing material into cells or releasing material Met for the same amino acid. to the exterior of cells, both via the cell membrane. } anticodon Pinocytosis is the ingestion of liquid into the cell G Initiation: AUG G incoming tRNA C Termination: UAA, UGA, UAG from vesicles formed from the cell membrane and Pr o phagocytosis is the ingestion of solid material. Redundancy and wobble (third base in the Three stages: initiation, elongation, termination codon) allow mutations to occur without Posttranslational modifications: affecting the protein. Folding by chaperones CARBOHYDRATE METABOLISM Point mutations can cause: Formation of quaternary structure Silent mutations, with no effect on protein Cleavage of proteins or signal sequences Glycolysis synthesis Occurs in the cytoplasm of all cells, and does not Covalent addition of other biomolecules Nonsense (truncation) mutations, which (phosphorylation, carboxylation, glycosylation, require oxygen. Yields 2 ATP per glucose. Important produce a premature stop codon prenylation) enzymes include: Missense mutations, which produce a codon Glucokinase: present in the pancreatic β-islet that codes for a different amino acid Control of Gene Expression in Prokaryotes cells as part of the glucose sensor and is Frameshift mutations, which result from responsive to insulin in the liver nucleotide addition or deletion and change Operons (Jacob–Monod model) are inducible or repressible clusters of genes transcribed as a single Hexokinase: traps glucose the reading frame of subsequent codons mRNA. Phosphofructokinase-1 (PFK-1): rate-limiting RNA is structurally similar to DNA except: regulator promoter operator structural regulator promoter operator structural step Substitution of a ribose sugar for deoxyribose Phosphofructokinase-2 (PFK-2): produces Substitution of uracil for thymine RNA polymerase RNA polymerase F2,6-BP, which activates PFK-1 Single-stranded instead of double-stranded R binds R Glyceraldehyde-3-phosphate dehydrogenase: repressor repressor inducer I inducer—repressor repressor—corepressor complex binds to produces NADH There are three major types of RNA in transcription: I complex cannot bind R C R C operator and represses R R to operator—structural genes are transcribed enzyme synthesis 3-phosphoglycerate kinase and Messenger RNA (mRNA): carries the message repressor cannot bind to operator by itself corepressor (end product) pyruvate kinase: perform substrate-level from DNA in the nucleus via transcription of inducible system repressible system phosphorylation the gene; travels into the cytoplasm to be translated Control of Gene Expression in Eukaryotes Glucokinase/hexokinase, PFK-1, and pyruvate kinase Transcription factors search for promoter and catalyze irreversible reactions. Transfer RNA (tRNA): brings in amino acids; recognizes the codon on the mRNA using its enhancer regions in the DNA. The NADH produced in glycolysis is oxidized anticodon Promoters are within 25 base pairs of the aerobically by the mitochondrial electron transport Ribosomal RNA (rRNA): makes up much of the transcription start site. chain and anaerobically by cytoplasmic lactate ribosome; enzymatically active Enhancers are more than 25 base pairs away dehydrogenase. from the transcription start site. 02_MCAT_QS_Biochem.indd 7 4/10/14 12:02 PM  Pyruvate Dehydrogenase Each NADH: 2.5 ATP; 10 NADH form 25 ATP LIPID AND AMINO ACID METABOLISM Converts pyruvate to acetyl-CoA. Stimulated by Each FADH2: 1.5 ATP; 2 FADH2 form 3 ATP insulin and inhibited by acetyl-CoA. GTP are converted to ATP. Lipid Transport 2 ATP from glycolysis + 2 ATP (GTP) from citric Lipids are transported via chylomicrons, VLDL, IDL, The Citric Acid Cycle acid cycle + 25 ATP from NADH + 3 ATP from LDL, and HDL. Takes place in mitochondrial matrix. Main purpose FADH2 = 32 ATP per molecule of glucose is to oxidize acetyl-CoA to CO2 and generate high- (optimal). 30–32 ATP per molecule of glucose TGL TGL Adipose energy electron carriers (NADH and FADH2) and GTP. is the commonly accepted range for energy CE CE Chylomicron Chylomicron Glucose yield Intestine (epithelium) (lymph) (blood) Lipoprotein Pyruvate Amino acids lipase PDH Glycogenesis and Glycogenolysis Cholesterol TGL Fatty acids Glycerol 3-P CE Fatty acids Acetyl-CoA Ketones Glycogenesis (glycogen synthesis) is the building of Chylomicron remnant Liver Alcohol glycogen using two main enzymes: TGL Triacylglycerol Triacylglycerol Citrate chol synthase Glycogen synthase, which creates α-1,4 Glucose VLDL Glycerol 3-P (blood) Oxaloacetate Citrate glycosidic links between glucose molecules. It Lipoprotein lipase Malate cis-Aconitase is activated by insulin in the liver and muscles. TGL Fatty acids NADH Branching enzyme, which moves a block of dehydrogenase chol + Isocitrate IDL NAD NAD + Isocitrate oligoglucose from one chain and connects it Malate dehydrogenase as a branch using an α-1,6 glycosidic link. Cholesterol Metabolism NADH CO2 Fumarase