BIO 107- Exam 3 Studyguide PDF

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Exam 3 Study Guide: Chapters 9, 17, and 18 Chapter 9: Gene Expression Can you define the term gene expression? ● Regulating gene expression- regulating the amount of protein produced by a cell Can you describe how messenger RNA (mRNA) is synthesized during the process of transcription? ● RNA polymerase: an enzyme that binds to a nucleotide at the beginning of every gene (promoter) ○ Unzips the double helix and matches the RNA nucleotides ● Producing a copy of the required gene, RNA nucleotides replace the DNA nucleotides Can you describe how proteins are synthesized during the process of translation? ● The process of decoding the copied RNA sequence and producing the protein that it codes for ● mRNA is used to produce the protein ● mRNA, amino acids, ATP, ribosomes, and RNA are needed ● mRNA is threaded between the small and large subunit of the ribosome ● tRNA: transfer RNA, carries amino acids Can you use the genetic code to identify the amino acid for which a DNA segment or a codon codes? ● Genetic code shows what mRNA codons code for which amino acids ○ There are 64 codons in total ○ 3 stop codons ○ EX: AUG is a start codon Can you define the term mutation, and explain how mutations can affect protein structure and function? ● Mutation: Any changes to the DNA sequence ○ Neutral mutation: Has no impact because the change codes for the same codon that the original mRNA codon coded for ○ Reading frame: may be altered if the triplet groupings are changed ○ Frameshift mutation: all nucleotides located after an insertion/deletion will be regrouped into different codons

Can you explain why and how some genes are expressed in some cell types but not others? ● Regulating gene expression- turning a gene on or off ● Repressors: bind to the promoter and prevent the RNA polymerase from binding ● Activators: help the RNA polymerase bind to the promoter which leads to gene expression Can you outline the process of cloning a gene using bacteria? ● Step 1: Remove the gene from the chromosome ○ Restriction enzymes: enzymes that act like highly specific molecular scissors to cut the portion of the gene wanted ■ Palindromes- specific sequences on DNA where it is cup ● Step 2: Insert the gene into bacterial Plasmid ● Step 3: Insert the recombinant plasmid into a bacterial cell Can you describe how plants and animals are genetically modified? ● Gene gun: A device that shoots metal-coated pellets covered with foreign DNA into plant cells ● Transgenic organism: the process when a gene from one species is incorporated into the genome of another species Can you list some of the health and environmental concerns surrounding genetic engineering? ● May not be completely safe for human consumption ● Genetically modified organisms may affect other organisms that are normal Can you describe the science behind and significance of stem cells and gene therapy? ● Stem cells: unspecified or undifferentiated precursor cells that have not been programmed to perform a specific function yet ○ They are totipotent (they can become any other cell type) ● Gene therapy: the process of trying to replace defective human genes with functional ones ○ Somatic cell gene therapy: the process of replacing or fixing a defective protein in the affected body cells Can you explain how and why cloning occurs? ● Occurs via nuclear transfer ○ Usually done for livestock or food for desirable traits - Therapeutic cloning- grow tissues or replace organs to replace damaged ones - Degenerative diseases- treat them - Def is slow breakdown of an organ and eventual organ failure

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Gene therapy- replacement of defective genes with functional genes - Somatic cell gene therapy- fixes or replaces defective protein only in affected cells - Fix or replace only defective protein Reproductive cloning- exact copy of organism Nuclear transfer- taking nucleus from adult cell and fusing it with egg cell that has nucleus removed

Chapter 17: Tissues Can you describe the structure and function of epithelial tissues? ● ● ● ● ●

Structure: Tightly packed sheets of cells that cover organs, outer surfaces line hollow organs, vessels and body cavities Attached on one side and free on the other Can be one or more layers Provides protection (from injury and UV light) secretion, and absorption

Can you compare the structures and functions of the six connective tissues? ● Loose connective Tissue ○ Most widespread connective tissue in animals ○ Holds organs in place ○ Structure: loose weave of fibers ■ Collagen and elastin create the matrix ● Adipose Tissue ○ Fat tissue that connects the skin to underlying structure ○ Insulates and protects organs ○ Synthesizes and stores fats ■ Fat is stored in cytoplasm of cells ○ Structure: m  ainly cells ● Blood ○ Circulates throughout the body through arteries, veins, and capillaries ○ Transports oxygen and nutrients to cells ○ Structure: liquid c ells of red blood cells, white bc, platelets, and plasma (matrix) ● Fibrous Connective Tissue ○ Forms tendons that connect muscles to bones and ligaments ○ fibroblasts=cells ○ Structure: parallel matrix that is densely packed ● Cartilage ○ Composed of cells (chondrocytes) that secrete substances ○ Connects muscles with bones ○ Smooth guiding and flexible support ○ Structure: dense matrix ● Bone

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Make up the skeleton and are connected at joints Supports and protects tissues and organs Marrow produces blood cells through the process of osteocytes Reservoir of calcium and minerals Structure: o steocytes, matrix- collagen and minerals

Can you compare the structures and functions of the three types of muscle tissues? ● Striated muscle ○ Function: mostly voluntary movement ■ Exception- cardiac muscle is involuntary and striated ○ Muscle that is banded ● Smooth muscle ○ Function: involuntary movement ■ Ex: digestive tract ○ Unbanded muscle ● Skeletal muscle ○ Attached to bone and produces all the movements of body parts ○ Voluntary movement ○ Striated muscle ● Cardiac muscle ○ Only in heart tissue ○ Striated but involuntary ○ Contractions for heartbeat Can you describe the structure and function of nervous tissues? ● Composed of neurons that conduct and transmit electrical impulses ● Helps body sense stimuli ● Processes stimuli ● Transmits signals out from the brain to the rest of the body Can you explain what an organ is and how organs interact in an organ system? ● Organ: A structure composed of two or more tissues packed together, working together to produce the specific function ● Organ system: Many organs that interact to perform a common function ● Cells, tissues, organs, organ systems, organism Can you list the structures and functions of the liver? ● Circulatory system ○ Synthesizes blood clots ○ Detoxifies harmful substances in the blood ○ Regulates blood volume ○ Destroys old blood cells ● Digestive system ○ Accessory organ- produces bile ● Structure- 4 lobes

Can you explain how positive and negative feedback mechanisms help in the maintenance of homeostasis? ● Negative feedback- glucose levels ○ Food is digested, glucose in blood increases, stimulates the pancreas to produce insulin, this hormone stimulates the liver to remove glucose from blood and store it as glycogen ● Positive feedback- child birth ○ During childbirth hormones cause more contractions which allow the baby to be delivered Chapter 18: Digestion Can you describe the structures and functions of the digestive system? ● Main function: breaks down and metabolizes food for energy found in the chemical bonds ● Mechanical digestion: teeth chew food to increase surface area ● Chemical digestion: secretion of saliva from salivary glands ● Digestion process: ○ Tongue: contains taste buds that help to taste food ■ Shapes food into balls (or bolus) and moves them to the back of the mouth ○ Pharynx: located at the back of the throat, separates into the trachea (leads to the lungs) and the esophagus (leads to the stomach) ○ Epiglottis: carries food to the stomach ■ Lower esophageal sphincter- prevents backflow of stomach contents to the esophagus ○ Peristalsis:  the process of rhythmic smooth muscle contractions that move the bolus of food down the esophagus ○ Stomach: large digestive organ ○ Chyme: Bolus mixed with digestive enzymes ■ Regulated by the pyloric sphincter ○ Small intestine: A long tube (about 20 ft) that is the main site for chemical digestion and absorption of nutrients into the bloodstream through the epithelium ○ Large intestine: (colon) the location where minerals that have not been absorbed are moved through to the rectum and anus Can you list the accessory organs of the digestive system, and outline their roles in digestive processes? ● Accessory organs: they are outside the digestive tract, but produce/secrete substances required for digestion ○ Liver: creates bile ○ Gallbladder- store and concentrates bile ○ Pancreas- p roduces digestive enzymes ■ Neutralizes stomach acids

■ Has enzymes that break down carbs, fats, proteins, nucl acids ■ accessory Can you list the structures composing the mammalian urinary system? ● Kidney: filters and cleanses circulating blood before sending the waste through the ureters to the bladder ● Urinary bladder: stores urine before it is released out of the urethra  Can you describe the steps in the process of urine excretion? -

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Urinary system- removes wastes and keeps imp materials for body Kidney- filter and cleanse blood - Has nephrons that are tubules - Capillaries surround the nephrons so that stuff can diffuse out of blood and into nephron - Renal arteries brings blood - 1---- filtration in bowman's capsule - At head of nephron - Glomerulus which is a bunch of blood vessels - Plasma of blood is forced through to glomerulus and then filters out water and small molecules - 2---- reabsorption - Water osmosizes out of nephron into kidney interior while going down nephron, sugars and amino acids taken out as well - Going up nephron--takes out salt so high salt contents at base of loop, low at top of loop - At end has water w urea - 3--- secretion - Active transport - Filtrate moves from nephron to collecting ducts that go to center of kidney - Water moves from this into kidney tissue - Water and materials go into capillaries then bloodstream and leave thru renal vein - Urine - made up of water and organic wastes - 4---- excretion - Urine leaves kidney and goes to bladder Ureters- connects to bladder Urinary bladder stores urine Urethra- expelled urine

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Alc- diuretic that increases amount of urine producing Helps regulate blood volume, acidity, and salt balance ADH- when blood pressure low, incr in permeability for water to go into bloodstream, visa versa for low blood pressure, also controls concentration of water in urine

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What process copies a sequence of DNA nucleotides into a complementary sequence of RNA nucleotides - Transcription Which molecule is not directly involved in the process of translation? - DNA Which molecule serves as the template during translation? - mRNA - Polymerase is enzyme that makes any kind of polymer - Trna brings amino acid to translate it What type of mutation produces no significant change in a functional protein? - Neutral mutation What molecular structure is used by geneticists to insert foreign DNA into a recipient bacterial cell that will replicate the foreign DNA? - Plasmid Which tissue type includes fat and blood? - connective - Epithelial is skin and outer layers- connected on one side but not the other What type of tissues can be transplanted from one person to another to reconstruct damaged joints? - Cartilage What is responsible for voluntary movement? - Conscious thought and striated muscle - Cardiac muscle striated but involuntary Which tissue type lines the intestines and helps in the absorption of nutrients? - Epithelial What process is responsible for the maintenance of blood glucose levels by the liver?** - Negative feedback - Blood glucose up--pancrease secretes hormone for liver to get rid of sugars, visa versa if blood glucose down then will metabolize sugars or smehing What activity of the liver makes it act as an accessory organ?** - Production of bile - Accessory organ- in digestive system, ones food doesn’t pass through, like pancreas What would a person born without an epiglottis not be able to do? - Swallow food without a high risk of choking

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- “So you just die without an epiglottis???” - person behind us Just before entering the small intestine, what is the pH of chyme? - Acidic (low pH) What is the contraction of smooth muscles that moves a bolus of food down the esophagus called?** - peristalsis - What is emulsification** A person can live a normal life without which digestive system organ? - Gallbladder What is emulsification? - The breaking up of fat molecules...