Human Biology EXAM 1 study guide all chapters + pictures PDF

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Notes for Exam 1 (Chapters 1,2,3, 19, 21)...

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Chapter 1 

What is homeostasis? o o

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o What are the basic characteristics of life? (How are we similar to other organisms?) o o o o

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Rely on homeostatic mechanisms Contain nucleic acids, proteins, carbs, and lipids Composed of cells (smallest unit of life) Grow and reproduce:  Use NRG & raw materials (chemicals) outside body to grow & reproduce Exhibit metabolism (specific chemical reactions) Exhibit irritability (we respond to environment) Are products of evolution and have adaptive traits

What makes humans unique? o

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Homeostasis: a state of relative constancy Homeostatic mechanisms are vital to survival and reproduction…exist at all levels of bio organization:  Cells  organisms  ecosystems  Health is homeostatic-dependent: break down of mechanisms  illness  Example: Stress results in disease by disrupting homeo mechs  Other: genetics, infectious agents (eg. Bacteria, fungi, viruses)

Brief history:  Social structure branched off from other primates 3-4 MYA  Diets: largely vegetarian, but we evolved into effective longdistance runners & hunters  Walk upright + have opposable thumbs So what really makes us unique though is…  Large brain evolution always hunted as a GROUP (+ other factors)  CRITICAL STEP! Paved the way we are today  Oh our brains… allows us:  Our ability to acquire and use complex languages  Our culture  Our ability to plan for the future  Our ability to shape the environment

What are the levels of biological organization, and how do they differ from each other?

How does the scientific method help us understand the world around us? o The systematic method is a logical approach to gathering info and reaching conclusions o Generally begins with observations that prompt questions  These observations lead to hypotheses and experiments to test them  We all routinely use it in our lives:  Example: walk in room o Observation: it is dark  prompts question: where is the switch?  hypothesis: there is a switch on the wall o New hypothesis: on the right side o New hypothesis  experiment  new hypothesis  experiment (over and over and over)  Theories: broad generalizations based on many experimental observations  Cannot be tested by single experiments (encompass too many pieces of information)  Modified over time as new info becomes available  Reasoning:  Inductive: based on observations  Deductive: specific statement or conclusion based on general rules o “if-then” o resulting general statement sets stage for more specific conclusions from it & further experimentation Clinical trials Chapter 2 

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What is the nature of atoms? o Electrons move in shells around the nucleus, and are held in their shell by the positive charge of proton o CanNOT be broken down into smaller units by chemical reactions o The # of protons in the nucleus of an atom is the atomic #

Elements: matter that contains only one type of atom Four elements comprise 98% of atoms found in all living things: (COHN) *carbon *oxygen *hydrogen *nitrogen

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What are molecules and compounds? o

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What are the ties that bind? o o

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Two or more atoms may combine to form molecules.  Molecule: two or more atoms held together by chemical bonds (eg. N2, O2….but NOT H20).  Compound: a type of molecule made up of two or more different kinds of elements (eg. H20, NaCl, C12H22O11)

Chemical bonds: when atoms bond to form more stable configurations containing 2 or more atoms Electrons are responsible for creating ties that hold atoms together  Several Types, but typically held together by:  Covalent: formed when 2 or more atoms share electrons in their outer shells  Ionic: electrostatic attractions b/w two oppositely charged ions o Ion: particle with (+) or (-) electrical charge due to an uneven # of protons & electrons o Form b/w 2 atoms when one loses an electron and the other gains an electron  Occurs b/c of the tendency of atoms to attain a complete outermost electron shell (eg. NaCl salt)  MORE protons than electrons? POSITIVE (+) charge

Why are some roles water plays in life? o Unique properties that make it a fundamental part of life  These unique properties arise from the polarity of water and the H+ bonds b/w its molecules  Polar covalent bonds: share characteristics of covalent and ionic bonds  Occur any time there is an unequal sharing of electrons by 2 atoms. These bonds bear a slight charge (+ or -)  Examples: water or sugar

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Hydrogen bonds form from the interaction b/w hydrogren and a negatively charged atom (form of polar bonding) Properties of Water:  Helps regulate body temperature, due to its high heat capacity and high heat of vaporization  Participates in many chemical reactions  Essential for cellular NRG production  Major component of all cells:  Solvent – eg. Get rid of wine stain   Transport medium  Lubricant  Water molecules may dissociate, or split into (H+) & hydroxide (OH-) ions  Ratio of water molecules to H+ and OH- in human body = about 500 million to 1… any change in H+ concentration can alter cells and organisms, and shut down biochemical pathways  Buffers are molecules that help keep pH values from changing dramatically (remove H+ from solution when too acidic (vice versa when too basic) Example: used to build and break things down: spray orange groves with water if they are freezing b/c it takes a lot of energy to freeze the water (from the air) so the air warms after you spray the plants! (heats up because energy was used)

What are the major groups of biological macromolecules? o Macros that consist of many small, repeating segments = polymers:  Composed of many monomers  Formed by dehydration synthesis  Are broken down by hydrolysis o Carbohydrates: monosaccharides, disaccharides, oligosaccharides (extended chains of short chains of sugars), and polysaccharides (long strings of sugars, like cellulose) o Lipids: triglycerides, phospholipids, steroids (eg. cholesterol and testosterone)  HDL (GOOD – hard to slow down) and LDL (BAD – sticks): high and low density lipids  When HDL is in cell membranes, body is more fluid o Proteins o Nucleic acids (DNA and RNA)

Chapter 3 

What differentiates eukaryotic and prokaryotic cells? o

Cell theory states the following:  Cell is the smallest unit of life  Cells make up all living things  New cells arise only from preexisting cells

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Examples:  Prokaryote: E. Coli or Salmonella (bacteria, archaea)  Eukaryote: animal cell or Us

What is the structure and function of the plasma membrane? o

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Plasma – fundamentally important for communication  Example: plasma is the reason all water moves out when in the ocean; it is the reason we would die in distilled water (the ions would attempt to balance because the water would rush in (osmosis)  EXPLODE. The outer surface of the cell Function:  Selectively permeable: controls what goes in/out of cell  Interstitial fluid  plasma membrane  cytoplasm (6): o Diffusion o Carrier proteins + diffusion o Osmosis  Hypertonic – solution concentration is higher  Ex: ocean (water moves out of us to try to balance us with ocean)  Isotonic – same  Hypotonic – lower solution concentration o Active transport o Endocytosis o Exocytosis  Maintains cell’s structural integrity & homeostasis  Glycoprotein cell-cell ‘self’ recognition  Recognize foreign invaders (eg. autoimmune disease)  Receptors provide cell-cell communication

Cell adhesion molecules: sticks cells together to form organs & tissues  Organelles in eukaryotes have similar outer membrane Structure:  Consists of lipids, proteins, and carbohydrates  Lipids (fats): biochemical characterized by their lack of water solubility  In the plasma membrane: form double layer called phospholipid bilayer (where proteins float freely) o Also has cholesterol lipid – makes things move fluidly!  Hydrophilic heads and hydrophobic tails 

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What are the main cellular organelles and what are their functions? o

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Nucleus: houses DNA - genetic info that controls cellular structure and function  Contained by double membrane called nuclear envelope  Nuclear pores allow communication b/w nucleus & cytoplasm  Chromatin: consists of DNA and associated proteins organized into chromosomes  Where RNA is produced from DNA Endoplasmic reticulum:  Protein synthesis  Rough ER – contains ribosomes, which produce proteins  Smooth ER – process other molecules not involved in protein synthesis The Golgi complex:  Protein synthesis  Modifies and packages proteins for extracellular use Mitochondria:  where most cellular respiration occurs – NRG in organic molecules is converted into usable NRG, in the form of ATP  outer and inner membranes  Cristae (folds) on inner membranes increase surface area for cell. Resp.

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What is the structure and function of the cytoskeleton?

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Network of tubules and filaments traversing the cytoplasm Three types:  Microtubules cilia move like oars (trachea, fallopian tubes) & flagella move like undulating whips (sperm)  Microfilaments  Intermediate filaments  How does your body get the energy it needs? o o

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Cellular respiration: an O2-requiring process that breaks down glucose  38 ATP per glucose molecule w/o energy!! (total output)  Releases CO2, H20, and NRG (energy)

Example of metabolism (all chemical rxns occurring in cell)  Anabolic: formation of complex molecules from simple ones requiring energy (building structures)  Catabolic: breakdown complex molecules into simple ones, releasing energy (Restoration)  Energy may also be derived by breaking down proteins, fats, and other carbs Four phases:  Glycolysis yields pyruvate, ATP, NADH in cytoplasm (little energy to break glucose)  Transition reaction breakdown of pyruvate  CoA acetyl (+ NADH) in mitochondria  Citric acid cycle modified many times in pathway – recycles 4C sugar (produces 6C citric acid when 2C acetyl CoA binds to 4C sugar) and produces ATP, NADH and FADH  Electron transport system (ETC) series of proteins embedded in inner surface of inner membrane  Converts energy in NADH and FADH into ATP  Electrons lose energy as they are passed from one protein to the next – used to make 32ATP per glucose molecule ATP splits off a phosphate and forms ADP when the cell needs energy directly, so new ATP can then be formed  Cells then have constant balance ADP – reactions to create new molecules whereas ATP is to create energy 

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Why o o o o

does fermentation matter? Without O2, the citric acid cycle and ETS shut down Cells must rely on glycolysis and fermentation to generate energy In fermentation, pyruvate is converted into lactic acid Important source of food for humans  Decompose dead matter (carbs + sugar)  Fermentation transforms glucose to ethanol, carbon dioxide and water. Anything above a certain level of ethanol kills bacteria (that's why they use an alcohol wipe on your skin before giving you a needle and those hand gel things contain a lot of alcohol).  Unfortunately it also kills your body too, which is why excessive consumption of alcohol is not advised.

Chapter 19 1. What differentiates the 2 types of cell division?  Zygote beginning – a single, diploid cell o Diploid: ½ chromosomes from mom; basically, 46 chromosomes (23 pairs) … 2 sets of chromosomes (haploid) o Now: trillions of cells  Mitosis: produces new somatic cells (body cells)  Meiosis: produces gametes (egg + sperm) – haploid cells 2. What are chromosomes?

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Tightly coiled combo of DNA and histones o DNA: contains info that controls cellular activity o Histones: help support/control gene activity (specific proteins DNA binds to) o Gene: specific DNA segment that directs protein synthesis 46 chromosomes per human somatic cell 23 chromosomes per human gamete o Sex chromosomes: one X or Y o Other chromosomes: autosomes *During cell division…histones bind to DNA  cause DNA to thicken/shorten

3. What are the steps in the cell cycle?  Mitosis involves division of 1 nucleus  2 identical daughter cells o One step in the creation  formation of daughter cells  Two major phases: interphase & cell division o Interphase: (3 parts) – primarily cell GROWTH (most of cell’s life)  G1: rapid growth and metabolic activity. Cell produces:  RNA  Proteins  Other molecules  S: the DNA replicates  Replicated DNA remains attached  The 2 copies are attached at the centromere  Each copy is a chromatiD (chromatinnnns make upppp chromatiddddds)  G2: (optional phase)  Additional cell growth  Protein synthesis  Mitochondria divide  Spindle fiber precursors form o Cell division  Two steps:  Nuclear division (mitosis)  Cytoplasmic division (cytokinesis)

4. What are the steps in mitosis? 1. Prophase – prep phase a. Chromosomes condense b. Nuclear envelope disappears & centrioles divide/migrate to opposite poles of the cell where… c. Spindle fibers form & attach to chromosomes 2. Metaphase – middle phase a. Chromosomes (consisting of TWO chromatiDs) line up at equatorial plate of dividing cell 3. Anaphase a. Attachments b/w sister chromatids break and (finally) chromosomes begin to separate!! 4. Telophase a. Chromosomes migrate (or are pulled) to opposite poles b. New envelope & nuclei form, each with TWO COMPLETE sets of chromosomes (uncoil) c. Cytokinesis divides cells into TWO daughter cells i. Usually occurs late in anaphase when envelope forms ii. Human cells: microfilaments lying beneath the plasma membrane contract, causing cytokinesis to occur 1. Each resulting daughter cell has 2 copies of each chrom. 5. How is the cell cycle regulated?  Chemical message produced in cytoplasm  External controls: o Hormones o Growth regulators o Cell contact – drives EVERYTHING.

What are the steps in meiosis?  Involves 2 sequential divisions of cells that creates haploid daughter cells called gametes – egg or sperm  Function (2): o Keeps chromosome # in a somatic cell constant from gen to gen o Increases genetic variation in the population  Two Sequential meiotic cell Divisions: o Meiosis I – separate homologues o Meiosis II – separate chromatiDs  *Differentiation following meiosis creates functional gametes (changes in shape and function of haploid cells) o Spermatogenesis o Oogenesis  Genetic variation: arises in egg & sperm from crossing over & independent assortment.

Chapter 21 1. What are DNA and RNA? Oh so similar... 

DNA: basis of most life, from bacteria to us o Structure: ladder-shaped molecule w/ twisted double helix  Each strand = string of nucleotides (~ 5 feet long!)

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 ~3 BILLion nucleotide pairs (base pairs) in DNA per cell  Double strands held together by H bonds o How does DNA work?  Unzips  each ORIGNAL strand serves as a template for the production of NEW complementary strands o What drives DNA replication?  DNA polymerase … It is a semiconservative process because it keeps half of the strand [when it replicates]. RNA: (ribonucleic acid) o Genes (segments of DNA) code for RNA, which codes to make specific proteins o 3 types of RNA molecules: (each involved with protein synthesis)  Messenger RNA (mRNA)  Transfer RNA (tRNA)  Ribosomal RNA (rRNA) Primary Similarities: 1) nucleic acids, 2) linked nucleotides, 3) sugarphosphate backbone, 4) 4 types of bases Primary Differences: Strand; deoxy v. ribose; Uracil; nucleus v. cytoplasm

2. How are genes converted into proteins?  On mRNA template through translation in the cytoplasm, using ribosomes o Ribosomes are the workbenches for proteins synthesis  Framework for which tRNA & mRNA interact  Each consist of a small and large subunit, w/ tRNA binding sites  Genetic code: ‘language’ of genes that converts DNA sequence into a sequence of amino acids (AA)

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o What are the ‘words’? Codons!  Codon: 3-base-sequence on mRNA. Each codes for specific AA  How many possible codon combos? 64…and 20 AA  What is the ‘stop’ signal? 3 codons (eg. AGU, ACC, etc.) Protein Synthesis: o 3 steps of Translation:  Initiation small ribosomal subunit and tRNA w/ complementary anticodon bind to mRNA at AUG  Why do they join? To form functional ribosome  Elongation enzymes in ribosome link appropriate tRNA to mRNA strand  then tRNA in 1st binding site leaves ribosome… the ribosomes move along the mRNA exposing the next codon while enzymes link the AA…REPEAT MANY TIMES  Termination when ‘stop’ codon moves into the ribosome  COMPLETED PROTEIN RELEASED: Release factors cause release of newly formed polypeptide and the separation of the rib subs and mRNA  Why stop? Because no tRNA to add in…we got a protein!

3. Why do mutations matter?  A single mutation can change the amino acid specified as well as the protein produced (slide 20, chapter 21). Some are beneficial; others are disastrous o Proto-oncogenes: control functions related to cellular respiration  Cause old cells to die so the total # of cells in us stays about the same…but if they stop working, than we start accumulating cells  Mutations in these genes can cause cancer.  Mutation means protection – if a codon has 3 bases, you can have a mistake that codes for the same AA  DNA replication usually results in the same daughter strand as the parent o However, changes in the genetic code may occur (mutations)  Mutations may involve: o Large changes in DNA o Insertion or deletion of nucleotides  What causes mutations? 1) Chemical, physical, or biological agents; 2) viruses; 3) ONLY mutated cells that produce gametes are passed to offspring 4. How do epigenetic factors and other mechanisms affect gene expression?  DNA is controlled by an array of chemical controls (only certain genes are active in a given cell)

o Many factors can affect this control code:  Vitamins  Toxic chemicals  Maternal behavior  Epigenome: part of the biological info a parent passes on to its offspring o Transcription changes how DNA binds to histones. The genes that cause you to gain weight (eg.) are affected by HOW DNA binds to the histones… the same DNA are read differently.  Gene expression control (4 levels): o At the chromosome coiling & uncoiling of chromatiN o At Transcription repression, induction, enhancement of gene o After transcription, but before translation removal of introns/ rearrangement of exons o At Translation RNA masking  Extra info: Methylation – the less transcribed b/c of histone change – you can control whether the DNA is exposed and exits (whether or not chromosome can unfold) … steroids affect promotors (turn some genes on/off) - how hormones affect transcription and translation 5. What are the implications of genetic for biotechnology?  Understanding how protein synthesis works means we can manipulate it o Genetic engineering: used to produce food, pharmaceuticals, and hormones, as well as treat diseases, improve diagnoses of diseases and gain insight into how cells function (eg. Athletic performance)  Example: beta keratin into rice for vitamin A o Recombinant DNA: DNA combined from more than one individual  GMO: by moving proteins around, you can’t eat a lot of things… not the same as hybrids (natural.. like a puggle)! All of our food is a result from biotech and hybridization...