Term
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Definition
| All of the proteins expressed by a genome. |
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Term
| Which is larger, proteome or genome? |
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Definition
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Term
| Why can more than one protein be expressed by a single gene? |
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Definition
| Alternative RNA splicing means the primary transcript can be altered to give a variety of mature transcripts, giving rise to several proteins. |
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Term
| Give three functions of non-coding RNA genes. |
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Definition
| Make rRNA/ tRNA/ RNA which controls gene expression. |
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Term
| What is the site of lipid synthesis in a cell? |
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Definition
| Smooth endoplasmic reticulum. |
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Term
| Where do all proteins begin their synthesis? |
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Definition
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Term
| What is the general purpose of intracellular membranes in eukaryotic cells? |
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Definition
| increase surface area for reactions |
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Term
| Effect of transmembrane signalling molecules on cytostolic ribosomes |
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Definition
| They halt translation and ribosomes migrate to the endoplasmic reticulum. They are inserted into a pore and commence protein synthesis there forming RER. (Rough endoplasmic reticulum.) The proteins produced form part of the membrane structure. |
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Term
| Give two functions of vescicles. |
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Definition
| Transport of molecules with in the cell or secretion. |
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Term
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Definition
| membrane-bound organelles containing a variety of hydrolases (enzymes that digest molecules) |
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Term
| Describe the structure of Golgi apparatus and state its functions. |
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Definition
| Series of flattened membrane discs; involved with post-translational modification and secretion of proteins. |
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Term
| What is the Cytosol of a cell? |
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Definition
| Liquid component of cytoplasm |
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Term
| Give three types of post translational modification and state which one is the major one*. |
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Definition
| Addition of carbohydrate*/ phosphate/ proteolytic cleavage. |
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Term
| What is the primary structure of proteins? |
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Definition
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Term
| What determines the primary protein structure? |
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Definition
| the sequence of amino acids |
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Term
| What type of bind links the amino acids in a polypeptide chain? |
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Definition
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Term
| Name the 4 types of R group in amino acids. |
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Definition
| Basic (+ve)/ acidic (-ve) / polar/ hydrophobic |
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Term
| Give four ways that R groups vary from each other. |
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Definition
| size, charge, reactivity, ability to bond with H |
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Term
| State the 3 types of secondary structure of proteins. |
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Definition
| Alpha helices/ beta-pleated sheets/ turns |
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Term
| Name the type of bond which creates secondary structure of protein. |
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Definition
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Term
| State the 5 types of interaction of the amino acid R groups that stabilises the tertiary structure of proteins. |
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Definition
| Hydrophobic interactions; ionic bonds; London dispersion forces; hydrogen bonds; disulfide bridges |
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Term
| Describe the quaternity structure of a protein |
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Definition
| Proteins with two or more connected polypeptide subunits |
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Term
| What is a prosthetic group on a protein? Give an example. |
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Definition
| A non-protein unit tightly bound to a protein and necessary for its function. eg. Haemoglobin (iron) or Chlorophyll (Mg) |
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Term
| Give two factors that influence the interactions of R groups in a protein. |
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Definition
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Term
| Define conformational change of a protein. |
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Definition
| A change of shape of the molecule |
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Term
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Definition
| Molecule which binds to a protein |
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Term
| What is the result of conformational change in a protein? |
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Definition
| a functional change in the protein |
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Term
| Explain why increasing temperature result in the protein becoming denatured. |
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Definition
| high temperature disrupts the interactions that hold the shape of the protein |
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Term
| What is the general effect of a ligand binding on a protein and changing its conformation? |
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Definition
| the confirmational change in the protein affects the activity of the protein. |
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Term
| Describe two features of allosteric proteins. |
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Definition
| they have a quaternary structure and have alternative binding sites (other than active sites for enzymes). |
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Term
| Explain cooperativity in proteins. |
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Definition
| binding of molecules to one unit results in a conformational change in the other binding sites, affecting their affinity |
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Term
| What is the function of modulators? |
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Definition
| regulate the activity of proteins by binding to the allosteric site. |
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Term
| Describe how the affinity of haemoglobin is altered if one subunit binds to oxygen. |
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Definition
| this causes a conformational change in the other subunits and increases their affinity for oxygen |
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Term
| Describe the effect of low pH on the ability of Haemoglobin to bind with oxygen. |
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Definition
| lowers the affinity of haemoglobin for oxygen |
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Term
| Describe the effect of high temperature on the ability of Haemoglobin to bind with oxygen. |
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Definition
| lowers the affinity of haemoglobin for oxygen |
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Term
| Name two factors which will aid the delivery of oxygen to actively respiring tissues |
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Definition
| Low pH and high temperatures |
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Term
| Nam e the molecule which can be added to or removed from a protein and cause a reversible conformational change. |
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Definition
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Term
| What is the function of protein kinases? |
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Definition
| transfer phosphate groups to other proteins |
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Term
| What is the function of protein phosphatases? |
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Definition
| remove phosphate groups from other proteins |
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Term
| What do protein phosphatases do to ATP? |
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Definition
| Remove the terminal phosphate group to form ADP. |
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Term
| Explain why phosphorylation of protein is useful. |
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Definition
| it is used by cells to regulate protein activity. |
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Term
| What type of charge is on a phosphate group? |
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Definition
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