3007984
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Flashcards by Reginald Arnedo, updated more than 1 year ago
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Created by Reginald Arnedo
almost 9 years ago
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| Question | Answer |
| List the types of biological molecules | 1. Lipids 2. Proteins 3. Carbohydrates 4. Nucleotide Derivatives |
| [...] is the solvent in which the chemical reactions of living cells take place | Water |
| What kind of bonding can water participate in? | Hydrogen Bonding |
| What makes water the perfect solvent? | its polarity |
| Define the effect of water molecules on polar molecules | Due to polarity and hydrogen bonding, polar molecules and ions are pulled apart forming ordered networks around them |
| Define the effect of water molecules on non-polar molecules | Forces non-polar molecules to congregtate together |
| Detail what happens to boiling point as water molecules form hydrogen bonds | Boiling point raises Result: Water remains in a liquid state in the cellular environment |
| Detail the effects of hydrophobic molecules in water | Hydrogen bonding and its strong coheisve forces squeeze hydrophoblic molecules away from water causing them to aggregate |
| Detail the effects of hydrophilic molecules in water | Hydrophilic molecules or ions dissolve easily in water because their negatively charged ends are attracted to the partial positive charge of water's hydrogen while their postively charged ends are attracted to the partial negative charge of oxygen. Water molecules solvate (surround) a hydrophilic molecule or ion |
| Separate from being a solvent, what ways can water act as a reactant or product? | Hydrolysis Dehydration |
| Define hydrolysis | Addition of water breaking a macromolecule is broken into two smaller molecules EX: Hydrolysis of ATP provides the body's major source of energy Digestion is the primary hydrolysis of macdromolecules, breaking a bond by adding the H and OH of water to either end |
| Define dehydration | Two molecules are combined to form a larger molecule and water is formed as a by product |
| Detail "Like dissolves" like | Polar molecules or ionic compounds are readily solvated by water Nonpolar molecules are not |
| What are the defining characteristics shared by all lipids | Nonpolar > Hydrophobic This defines the behavior of lipids in the watery environment of the cell |
| List the three categorical roles of lipids | 1. Energy Storage 2. Cellular organization and structure, particuilarly in the membrane 3. Provision of precursor molecules for vitamins and hormones |
| List the major groups of lipids | 1. Fatty acids 2. Triaglycerols 3. Phosphlipids 4. Glycolipids 5. Steroids 6. Terpenes 7. Waxes 8. Sphingolipids |
| What leads to the energy storage of lipids? | Long carbon chains |
| What leads to the cellular organization and structure of lipids? | Fats assemble into barriers separating aqueous environments because they are hydrophobic |
| What leads to the provision of precursor molecules for vitamins and hormones of lipids? | signaling molecules can pass through cellular membranes |
| Fatty acids have an [...] amount of carbons | Even |
| Fatty acids are the building blocks for [...] | Most complex lipids |
| Which lipid acts as fuel for the body? | Fatty acids |
| What are fatty acids the components of? | Phospholipids, glycolipids, and shingolipids of cell membranes |
| What are fatty acids comprised of? | Composed of long chains of carbons truncated at one end by a carboxylic acid |
| What are the two types of fatty acids? | Saturated Unsaturated |
| What type of carbon-carbon bonds do saturated fatty acids have? | single c-c bonds |
| What type of carbon-carbon bonds do unsaturated fatty acids have? | One or more c-c double bonds |
| [...] of fatty acids liberates large amounts of [..] energy for a cell | Oxidation Chemical |
| Converse to energy liberation, what else can fatty acids be used for? | Energy storage |
| What allows fatty acids to store more energy pre gram than any other macromolecule? | high concentration of carbon-hydrogen bonds |
| In what form do most fats reach cells? | free fatty acids Fatty acid chains not attached to a backbone, rather than a tricylglyercols |
| What other categories of lipids are sometimes referred to as fatty acids? | Triacylglyercols Phospholipids Glycolipids |
| Detail Triacylglycerols | Triglycerides, fats and oils Glycerol (3 Carbon Backbone) + three fatty acid chains Function: Store energy, provide termal insulation and padding |
| Define Adipocytes | Adips - Fat kytoes - Cell Fat cells - specialized cells whose cytoplasm contains almost nothing but triglycerides |
| What are phospholipids | lipids with a phosphate ground attached |
| What are phosphoglycerides | Phospholipids that have a glycerol backbone with a polar phosphate group replacing one of the fatty acids. |
| Where does the phosphate group lie in a phosphoglycerol | The phosphate group lies on the opposite side of the glyercol from the fatty acids. This makes the phospholipid polar at the phosphate end and nonpolar at the fatty acid end |
| Define amphipathic | molecules that have a polar and non polar end |
| What makes phospholipids well suit as the major component of biological membranes? | It is amphipathic |
| Detail Glycolipids | Similar to phosphoglycerides except they have 1 or more carbohydrates attached to the three-carbon glycerol backbone instead of the phosphate group. Amphipathic Found in abundance in the membranes of myelinated cells in the human nervous system |
| Detail bilayer membranes with phospholipids | In bilayer membranes, the polar heads of phospholipids face toward the watery environment within and outside the cell, while the tails create a nonpolar inner layer within the membrane, creating a barrier to polar molecules that allows the regulation of their passage in and out of the cell |
| Detail Sphingolipids | Similar to phsphoglycerides Long chain fatty acid + polar head group Instead of glycerol, the backbone molecule is spingosine (Amino alcohol) Make up part of the cell membrane along with phospholipids, glycolipids, and steroids |
| Detail Sphingomyelin | A type of sphingolipid that has a phosphate group attached to the sphinosine backbone, thus is a phospholipid but not a phosphoglyceride |
| Detail Steroids | Four ringed lipid structures Hormones, Vit-D, Cholesterol |
| Detail Terpenes | 6th class of lipids often part of pigments. Includes Vit-A |
| Detail Waxes | Lipid formed by an ester linkage between a long-chain alcohol and a long-chain fatty acid Variety of cuntions determined by characteristicwater-repellent texture |
| What are eicosanoids | 20 of them. Another class lof lipids Prostaglandins, thromboxanes, and leukotrienes Released from cell membranes as local hormones that regulate: Blood pressure, body temp, and smooth muscle contraction Aspirin is an inhibitor of prostaglandin synthesis |
| How are lipids transported in blood? | By lipoproteins since lipids are insoluble in aqueous solution |
| Detail lipoproteins | Lipid core surrounded by phospholipids and apoproteins It's able to dissolve lipids in its hydrophobic core and then move freely through the aqueous solution due its hydrophillic shell |
| How are lipoproteins classified? | By their density Greater the ratio of lipid to protein, the lower the density |
| What are the major classes of lipoporteins in humans? | chylomicrons VLDL - very low density lipoproteins LDL - low density lipoproteins HDL - high density lipoproteins |
| Detail the major functions of lipids | 1. Phospholipids serve as a structural component of membranes 2. Triacylglycerols store metabolic energy and provide thermal insulation and padding 3. Sterolids regulate metabolic activities 4. Some fatty acids (eicosanoids) even serve as local hormones |
| *** How is genetic information a mechanism of regulation? | It provides the tools necessary for the moment to moment cellular processes that help cells survive in fluctuating environments / cellular activities of an organism's lifletime Allows these processes and adaptations to be passed on to future generations / passing of hereditary traits |
| How is the genetic exhibition across living organisms? | Remarkable amount of similarity |
| How is the variation of nucleotide sequences in humans? | Small Human DNA differs between individuals at approx. 1 nucleotide out f every 1200 0.08% |
| Why do the similarities in genetic information across living organisms exists? | The genetic language to carry out the basic processess of life is universal |
| How does the amount of uniformity in genomes of living organisms demonstrate itself in DNA? | Small changes can make a significant difference |
| From a genetics standpoint, what causes differences between organisms? | 1. Variation in nucleotide sequence 2. Differences in regulation of how those sequences are expressed **The sequence of nucelotides alone does not determine what an organism is like how and when a sequence is read is also important |
| Define genome | Raw material of genetics: complete sequence of nucelotides of the genetic material Usually DNA but can be RNA in some viruses |
| What does reading the genome allow cellular machinery to do? | Make all the proteins and products that sustain life |
| What is illustrated by he ability to alter the expression of genes in the genome? | All the different types of cells in the human body |
| Define epigenetics | Changes made around the genome that do not alter the actual nucelotide sequence. These changes instruct the cellular machinery on how to read the genome, thereby altering gene expression. They do not change the genome itself |
| What are some examples of epigenetics | Attachment of chemical markers to the genome Histone protein modification Use of non-coding RNA's to influence gene expression |
| What is the purpose of epigenetic control | To provide a system of regulation that allows gene expression to adapt to the needs of the organism |
| What allows gene expression to adapt to changes in the organism's internal and external environment? | Continually changing epigenetic control of gene expression |
| In addition to changing gene expression through an individual's lifetime, [...] and [...] can be passed down from one generation to the next | Epigenetic chemical markers Histone modifications |
| What is genetic sequence a set of | functional units called genes |
| Define gene | nucleotide sequence that can code for a certain product or set of products depending on factors such as alternative splicing and protein modification |
| Relate genes to traits | Genes are also a unit of heredity A sequence of nucleotides that codes for a trait |
| Define Trait | genetically influence characteristic |
| What is the function of the genome over the course of a cell's lifetime | To code for the products, usually proteins, that are necessary for cellular processes |
| Detail Central Dogma of gene expression | DNA is transcribed to RNA RNA is translated to Amino Acids to form a protein All living organisms use this to express their genes |
| How do retroviruses store their information and express their genes | Store their information as RNA First ocnvernt RNA to DNA in order to express their genes |
| Three primary functions of geneic code | 1. Coding for necessary products during the lifetime of a cell 2. Copying genetic information for the creation of new cells within an organism 3. Passing on genetic information to the next eneration |
| Define chromasomes | Arranged double stranded DNA sequences in eukaryotic cells |
| Why is the compact organization of chromosomes necessary? | Because of the large size of eukaryotic genomes |
| What do chromosomes allow the genome to be? | Compressed and organized |
| What does a chromosome consist of | compactly wrapped DNA and protein in a hierarchy of organizational levels |
| How are the sections of DNA not in used wrapped? | Wrapped tightly around globular proteins called histones |
| Detail histone structure | Have a basic functional group that gives these proteins a net positive charge @ normal pH of the cell Net + charge attracts net - charge of DNA strands and helps in the wrapping process |
| Detail nucelosome | Eight histones wrapped in DNA |
| What do nucelosomes wrap into? | coils called solenoids |
| What do solenoids wrap into? | Wrap into supercoils |
| Define chromatin | The entire DNA / Protein (Including a small amount of RNA) compex 1/3 DNA 2/3 Protein Small amount of RNA |
| Detail how chromatin got its name | Large amount of basic AA content in histones allows chromatin to absorb basic dyes |
| Is their variation in how chromatin is compact? | yes |
| The cellular machinery that reads genetic code can only do so when chromatin is [...] | Uncoiled |
| Define heterochromatin | Chromatin that is tightly condensed |
| Define constitutive heterochromatin | Chromatin permanently coiled |
| Define euchromatin | chromatin that is uncoiled and ready to be transcribed |
| When is euchromatin coiled? | During nuclear division |
| Define single copy DNA | Nucleotide sequences represented by only one copy of a nucelotide sequence Associated with euchromatin regions being actively transcribed |
| What type of DNA to nucleotide sequencees that code for protein often contain? | single copy DNA |
| What type of DNA is often found in non-coding regions of DNA | Reptitive DNA Found only in eukaryotes |
| Define reptitive DNA | DNA with multiple consectuvie copies of the same nucleotide sequence and remains tightly coiled in regions of heterochromatin |
| Where is DNA found in animals? | Nucleus Mitochondira |
| What highly regulates the coiling and uncoiling of chromatin? | epigenetic controls according to the needs of the cell |
| What helps control which sections of DNA are tightly wound and which are accessible to cellular machinery? | Chemical changes to histone proteins |
| What is the most common example of epigenetic regulation through chemical change | DNA methylation |
| What can also control which coding sequences are unwound and transcribed? | Chemical epigenetic changes |
| Define DNA methylation | Addition of an extra methyl group to particlar cytosine nucelotides |
| What does Methylation do to DNA | Causes it to be wound more tightly |
| Relate methylated sections of DNA to cellular machinery and transcription | It is inaccessible to cellular machinery and cannot be transcribed thus the expression of genes in these sections is reduced |
| Define Non-Coding RNA | (ncRNA) Sections of RNA that do not code for protein products |
| What does ncRNA do? | Contribute to the regulation of the chemical changes that affect chromain structure |
| Relate genetics to how people become more prone to conditions such as asthma, obesity, and anxiety | Patterns of DNA methylation can be inherited from previous generations Increasing evidence that life experiences of your ancestors can affect gene expression in your lifetime These inherited epigenetic changes can make people more prone to asthma, obesity, and anxiety |
| What type and how many DNA are in the nucelus of a human somatic cell? | 46 Double-Stranded DNA molecules |
| Chromatin associated with each of the 46 double stranded DNA in humans is wound into a [...] | chromosome |
| Define homologues | Each chromosome possesses a partner that codes for the same traits as itself |
| How many homologous pairs of chromosomes do humans have? | 23 |
| Define diploid | Any cell that contains homologous pairs of chromosomes |
| Define haploid | Any cell that does not contain homologues |
| What phase do cells spend a majority of their lives in? | G0 - Non growing phase serving their various functions of the body and producing proteins for that purpose |
| What are the two processes genes undergo to make products? | Transcription Translation |
| Define transcription | Process by which DNA is manufactured from a DNA template an RNA transcript, which essentially copies the info from DNA, is created |
| What are the different types of RNA that different genes can code for | rRNA - ribosomal tRNA - transfer RNA snRNA - small nuclear RNA mRNA - messenger RNA |
| Which types of RNA are functional end products that serve important purposes in the cell | rRNA tRNA snRNA |
| What type of RNA serves as the message that is translated for protein production? | mRNA |
| What is the largest portion of RNA transcribed as? | mRNA |
| Define translation | The nucleotide sequence of the RNA transcript is translated into the language of amino acids, which are then strung together to form a functional protein |
| What is the purpose of transcription | to create an RNA copy of a DNA template |
| Relate transcription to gene expression | form of regulation of gene expression |
| What would happen if transcription did not exist and the whole genome was translatged directly to proteins? | Every cell in an organism would be the same |
| What are the three stages of transcription | 1. Initiation 2. Elongation 3. Termination |
| Detail initation in transcription | The beginning of transcription A group of DNA binding proteins called transcription factors identifies a promoter on the DNA strand A promoter is a sequencde of DNA nucelotides that designates a beginning point for transcription At the promoter, the transcription factors assemble into a transcription initiation complex which includes RNA polymerase |
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