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119 Cards in this Set
- Front
- Back
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Structural isomers
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substances with the same molecular formula that differ in the covalent arrangement of their atoms
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Stereo isomers
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substances with the same arrangement of covalent bonds, but the order in which the atoms are arranged in space is different
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Cis trans isomer
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diastereomers associated with compounds that have carbon-carbon double bonds (cis larger item together) (trans larger items opposite)
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enantiomers
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substances that are mirror images of each other and that cannot be superimposed on each other
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hydroxyl
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-O-H polar found in alcohols
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carbonyl
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O=C polar found in aldehydes and ketones
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carboxyl
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weakly acidic found in organic acids
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amino group
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weakly basic found in amino acids
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sulfhydryl
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non polar found in some amino acids
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phosphate group
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weakly acidic found in phospholipids and nucleic acids
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methyl group
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non polar, hydrophobic, found in lipids and other membrane components
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carbohydrates
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made of carbon, hydrogen, and oxygen (CH2O ration) ex. Sugars sartches cellulose.
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Starch
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main energy storage carbohydrate of plants
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Glycogen
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main energy storage carbohydrate of animals
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Cellulose
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major structural component plant cell walls
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Lipids
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hydrophobic, energy storage membrane compound
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Saturated fats
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no C-C double bonds, solid at room temp
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Unsaturated fats
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one or more C-C double bonds, liquid at room temp
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Phospholipids
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a diacylglycerol molecule, a phosphate group esterified to the third -OH group of glycerol, an organic molecule (such as choline) esterified to the phosphate. (polar head, non polar tails)
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Proteins
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formed from amino acid monomers
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Amino acids
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amino group, carboxyl group, and a variable R group
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Primary structure
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the sequence of amino acids in the peptide chain
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Secondary structure
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the alpha helix, or beta pleated sheets
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Tertiary structure
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the overall folded shape of a single polypeptide chain
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Quaternary structure
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results from interactions between two or more separate polypeptide chains
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Purines
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double ring, adenine, guanine,
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Pyrimidines
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single ring, cytosine, thymine, and uracil
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anabolic reactions
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are processes that build complex molecules from simpler ones usually endergonic
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catabolic reactions
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are processes the break down complex molecules into simpler ones usually exergonic
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cytoplasm
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everything outside the nucleus and within the plasma membrane, contains fluid, cytosol, and organelles
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nucleoplasm
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everything within the nuclear membrane
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nucleus
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cell control center ~5um, surrounded by nuclear envelope, double membrane with nuclear pores to regulate passage through the envelope
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chromatin
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DNA protein complex, unpacked DNA ready for transcription and replication
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chromosomes
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condensed packed DNA ready for cell division
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nucleoli
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regions of ribosome subunit assembly, rRNA transcribed from DNA here, proteins (imported from cytoplasm) join with rRNA at a nucleolus to form ribosome subunits
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ribosomes
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granular bodies with three RNA strands and about 75 associated proteins, serve as the sites of translation of genetic information into protein sequences
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endomembrane system
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a set of membranous organelles that interact with each other via vesicles. ER, Golgi apparatus, vacuoles, lysosomes, microbodies, and in some definitions the nuclear membrane and the plasma membrane
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smooth ER
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primary site of lipid synthesis, many detoxification reactions, and sometimes other activities
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rough ER
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ribosomes that attach there insert proteins into the ER lumen as they are synthesized
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golgi apparatus
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a stack of flattened membrane sacs (cisternae) where proteins further processed, modified, and sorted [the “post office” of the cell] cis is receiving end trans is shipping out end media is middle
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lysosomes
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small membrane-bound sacs of digestive enzymes, can also fuse with dead or damaged organelles and digest them
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peroxisomes
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sites of many metabolic reactions that produce hydrogen peroxide (H2O2), which is toxic to the rest of the cell. Detoxification of alcohol in liver cells.
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mitochondria
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- site of cellular respiration
- composed of double membrane - inner membrane folded forming cristae - matrix is inner space of inner membrane - have own DNA |
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plastids
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organelles of plants and algae that produce and store food
have own DNA like mitochondria amyloplasts- starch storage chromoplasts- color in petals and fruits chloroplasts- for photosynthesis |
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chloroplasts
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- very similar to mitochrondria
- double membraned - internal membrane is stroma - contain stacks of thylakoids (granum) - contain chlorophyll and other accessory pigments (caretenoids) |
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thylakoids
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flat sack in chloroplasts containing chlorophyll
location of light dependent reactions |
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granum
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stack of thylakoids
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cytoskeleton
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dense network of protein fibers that provides needed structural support
also responsible for cell movement, cell division, and transporting materials |
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microtubules
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-made of protein tubulin
-maintain cell shape (compression resistant girders) -motility in cilia and flagella -spindle fibers in cell division -hollow tubes, walls made of 13 columns of tubulin molecules -track for motor proteins which transport vesicles -25nm with 15nm lumen |
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microfilaments
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-made of protein actin
-maintain cell shape (tension bearing elements) -motility in pseudopodia -muscle contraction -creates cleavage furrow in cell division -two intertwined strands of actin -7nm |
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intermediate filaments
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-proteins from keratin family
-maintain cell shape (tension bearing elements) -not easily broken down (more permanent) -form a web across a cell reinforcing it -8-12 nm |
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centrosome
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site of microtubule production
contain centriole which are made of 9 sets of microtubule triplets |
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cell wall
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-plants have thick cell wall composed of cross linked cellulose fibers
-fungi with thinner wall made of chitin |
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phospholipid
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-glycerol linked to 2 fatty acids
-hydrophilic head made of polar organic model linked via a phosphate group to the glycerol backbone -hydrophobic tail made of the 2 fatty acids |
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amphipathic
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having distinct hydrophobic and hydrophilic regions
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unsaturated fats in bilayer
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phospholipids with unsaturated fats have kinks in tail causing the phospholipids to become more spaced out resulting in a more fluid like membrane
preferred at colder temperature |
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membrane fluidity control
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change the temperature (fastest)
change fatty acid profile (slow) use buffers such as cholesterol |
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integral proteins
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are amphipathic proteins that are firmly bound to the membrane, and can only be released from the membrane by detergents
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peripheral proteins
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proteins non embedded in the membrane but attached ionically or by hydrogen bonds with hydrophilic region of integral protein
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selective permeability
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most permeable by small molecules and lipid soluable substances. ex. water co2 and O2
amino acids, sugars, and ions do not pass through easily |
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diffusion
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is the net movement of particles from an area with a high (initial) concentration to an area with a low (initial) concentration
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osmosis
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diffusion of a solvent across a membrane
solvent is typically water in biology |
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isotonic
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same concentration
equal movement of water |
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hypertonic
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higher osmotic pressure
water will flow into it |
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hypotonic
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lower osmotic pressure
water will flow out |
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facilitated diffusion
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when net transport follows a concentration gradient, but proteins are needed to assist in transport
(requires no energy) |
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anchoring junctions
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-hold cells tightly together; one common type in animals is the desmosome.
-material can pass in space between cells -not involved in transport of materials |
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tight junctions
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-used to seal off body cavities
-material can not pass between cells held together by these -not involved in transport of materials |
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gab junctions
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-between animal cells
-act as selective pores -can form 2nm pore for small molecules to pass |
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plasmodesmata
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-selective pores between plant cells
-connect the plasma membranes of 2 cells |
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aerobic respiration
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redox reaction oxidizing glucose to CO2 and reducing O2 to H2O
consists of 4 processes to convert glucose to ATP |
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glycolysis
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breakdowns glucose and creates 2ATP 2NADH and 2 Pyruvates
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chemotrophs
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can only get energy directly from chemical compounds
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phototrophs
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get energy from light
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photoautotrophs
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carry out photosynthesis
green plants and algea |
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C4 pathway
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-used by plants in intense light
-increases the amount of CO2 -alters the location of CO2 fixation -corn sugarcane crabgrass |
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CAM pathway
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-used by plants in arid condition
-allows CO2 uptake to occur at night when stomata are more open -alters time of CO2 fixation -desert plants, cacti |
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What must genetic material do?
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1. the genetic material must be able to replicate itself
2. must be able to direct and control living processes |
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DNA helicase
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unwinds and opens the DNA in replication
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topoisomerase
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break and rejoin strands, resolving knots and strains that occur
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DNA polymerases
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polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand
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direction of synthesis
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adds nucleotides to 3' end
synthesis can only take place in 5' to 3' direction |
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source of new nucleotide
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the nucleotide added is from a deoxynucleotide triphosphate; two phosphates are released in the process
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functions of primase (4)
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1. DNA polymerase can only add onto an existing strand, so it can�t start the strand
2. primase starts the strand by making an RNA primer that is a few (usually about 10) ribonucleotides long 3. DNA polymerase can then add nucleotides starting at the end of the RNA primer 4. the RNA primer is later degraded and (usually) replaced with DNA |
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leading strand
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the leading strand, has its 3� end at the fork; thus, its synthesis can proceed continuously, in the direction that the fork moves
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lagging strand
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lagging strand has its 5� end at the fork; it must be synthesized in the �opposite direction� from the leading strand
� the lagging strand is thus made in short (100-1000 nucleotides) Okazaki fragments � fragments are later connected by DNA ligase (which also joins together DNA strands when replication forks meet) |
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nucleosomes
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nucleosomes are the main packaging mechanism for eukaryotic DNA
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difference between RNA and DNA
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uracil (U) functions in place of T in RNA
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mRNA
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messenger RNA: copies the actual instructions from the gene
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tRNA
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transfer RNA: links with amino acids and bring them to the appropriate sites for incorporation in proteins
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rRNA
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ribosomal RNA: main structural and catalytic components of ribosomes, where proteins are actually produced
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mutagens
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DNA-damage inducers are called mutagens
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point mutation
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mutations that result in the substitution of one base for another are referred to as point mutations or base substitution mutations
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silent mutation
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if the point mutation does not actually cause a change in what amino acid is coded for, it is called a silent mutation
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missense mutation
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if the point mutation causes a change in what amino acid is coded for, it is called a missense mutation
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nonsense mutation
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if the point mutation result in the formation of a stop codon where an amino previously was coded for, it is called a nonsense mutation
nonsense mutations result in the premature termination of the protein sequence, and thus an active protein is usually not formed |
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frameshift mutation
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mutations that shift the reading frame (when nucleotides are either added or deleted) are called frameshift mutations
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nondisjunctio
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mistake in cell division where chromosomes do not separate properly in anaphase
� usually in meiosis, although in mitosis occasionally � in meiosis, can occur in anaphase I or II |
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aneuploidy
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missing one copy or have an extra copy of a single chromosome
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turner syndrome
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X_ female
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Klinefelter syndrome
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XXY Male
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down syndrome
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extra 21 chromosomes
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assumptions of hardy weinburgh
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1. large population size (due to statistical constraints, to minimize genetic drift)
2. no migration � no exchange of alleles with other populations (no gene flow) 3. no mutations of the alleles under study occur 4. random mating of all genotypes 5. no natural selection |
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genetic drift
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a change in gene frequencies of populations because of small population size
genetic drift tends to decrease genetic variation within a population and increase genetic variation between populations |
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positive assortive mating
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positive assortive mating selection for the same phenotype; works like inbreeding for the genes governing that phenotype, and for loci closely linked to those genes
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negative assortive mating
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selection for the opposite phenotype
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stabilizing selection
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selecting against phenotypic extremes
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directional selection
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permits species to adapt to environmental change by favoring selection of one extreme over the other
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disruptive selection
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when more than one extreme phenotype is favored over intermediate phenotypes
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prezygotic barriers
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prezygotic barriers � prevent fertilization (zygote formation) between gametes from two species
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habitat isolation
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habitat isolation (or ecological isolation) � isolation by differences in habitat occupied at the time of mating; examples: some garter snakes; some flycatchers
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temporal isolation
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temporal isolation � isolation by differences in timing of mating; examples: mating seasons in some skunks; flowering time in some plants; mating time in some fruit flies
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behavioral isolation
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behavioral isolation � differences in behavior that cause reproductive isolation; examples: mating calls, courtship patterns, and other mating rituals; can be an aspect of sexual selection (selective pressure that comes from mating choices)
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mechanical isolation
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mechanical isolation � differences in physical aspects make successful mating impossible; examples: many flower species; dragonflies may attempt interspecies mating, but the physical structure of their genitalia prevents successful mating
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gametic isolation
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gametic isolation � mating occurs, but the sperm and egg can not fuse; examples: sperm cannot penetrate the egg of the different species, such as between sea urchins species, as well as in many other animal species; in plants, often pollen grains do not get the proper signal to germinate when on a stigma of a different species
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hybrid inviability
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hybrid inviability � (the most common type of postzygotic barrier) normal development of the zygote formed from the mating of two species does not occur and the embryo is aborted, or if development is completed the offspring is very frail; examples: crosses between different iris species, cross between bullfrog and leopard frog; crosses between some salamander subspecies
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hybrid sterility
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hybrid sterility � a zygote of a hybrid proceeds through normal development, but is reproductively sterile
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hybrid breakdown
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hybrid breakdown � a zygote of a hybrid proceeds through normal development, and the interspecific hybrid reproduces, but the F2 generation and beyond have problems with reproduction; examples: crosses between sunflower species result in 80% hybrid breakdown in the F2 generation; crosses between some rice strains
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structure of DNA
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sm->lg
nucleosomes wrap around histones which coil and condense into chromatin which form chromatid then chromosomes |
