BS801 Genes R Us Questions for study: 1. What functions do transcription and translation carry out, and where are they carried out in the cell? Transcription: process of creating an equivalent RNA copy of a sequence of DNA Transcription is the first step leading to gene expression. The stretch of DNA transcribed into an RNA molecule is called a transcription unit and encodes at least one gene. Occurs in nucleus of the cell Translation: Translation is the production of proteins by decoding mRNA produced in transcription. Translation occurs in the cytoplasm where the ribosomes are located. In translation, messenger RNA (mRNA) is decoded to produce a specific polypeptideaccording to the rules specified by the genetic code. This uses an mRNA sequence as a template to guide the synthesis of a chain of amino acids that form a protein. 2. Which of the kingdoms of organisms are characterized by unicellularity (the organism has only one single cell)? Protista 3. Bacteria and archaea are both prokaryotes, but they have very different characteristics. How would you compare archaea and bacteria? Archaea cell membrane contains ether linkages cell wall lacks peptidoglycan genes and enzymes behave more like Eukaryotes have three RNA polymerases like eukaryotes extremophiles 4. What process can lead to shrinkage or swelling of a cell? Osmosis 5. What are the different kinds of fibers that make up cytoskeleton? Cells contain elaborate arrays of protein fibers that serve such functions as: Bacteria cell membrane contains ester bonds cell wall made of peptidoglycan have only one RNA polymerase react to antibiotics in a different way than archea do
1. 2. 3. 4. 5.
establishing cell shape providing mechanical strength locomotion chromosome separation in mitosis and meiosis intracellular transport of organelles
The cytoskeleton is made up of three kinds of protein filaments:
Actin filaments (also called microfilaments) Intermediate filaments and Microtubules
6. What is a triglyceride? Cholesterol is a type of fat. How is it different from other lipids? What type of lipid makes up the plasma membrane of cells? Triglyceride: glyceride in which the glycerol is esterified with three fatty acids What's the difference between triglycerides and cholesterol? Triglycerides and cholesterol are separate types of fats (lipids) that circulate in your blood. Triglycerides provide your body with energy, and cholesterol is used to build cells and certain hormones. Because triglycerides and cholesterol can't dissolve in blood, they circulate throughout your body with the help of proteins that transport the lipids, called lipoproteins. Triglycerides Triglycerides are the basic chemical form of fat. Chemically, the structure of triglycerides is one molecule of glycerol (CHOH2-CHOHCHOH2) attached to three fatty acids, such as oleic acid or linoleic acid. Triglycerides come from either ingestion of dietary fats or
through the conversion of unused calories. Triglycerides are stored in the body's fat cells until the body needs to metabolize them for energy. Cholesterol Cholesterol, with a chemical structure is C27-H4-OH, acts as both a precursor for hormones and as a part of cellular membranes. The human body produces 2 grams of cholesterol per day, making up about 85 percent of blood cholesterol levels. The other 15 percent comes from a person's diet. Most cholesterol from diet comes from oils and fats in foods. The body produces bile acids from cholesterol; bile acids break down oils and fats. The blood transports cholesterol by lipoproteins, which easily clump together with fats. The two different types of lipoproteins are low-density lipoproteins (LDL) and high-density proteins (HDL). The cell membrane consists of three classes of amphipathic lipids: phospholipids,glycolipids, and steroids. 7. What are the elements that are generally found in the molecules that make up living organisms (aka “biomolecules”)? CHNOPS elements: Carbon,...
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