Chaperones • Some proteins have trouble finding or forming their correct conformation. A protein chaperone can accompany the original protein and supervise and help it to assemble correctly. • PrPSc is acting like a chaperone in BSE but not positively. • PrPC is the protein that is getting influenced negatively. • This influence will turn all of the PrPC into PrPSc and aggregate inside the cell and kill the cell (Reynaud,
| | | A) | endoplastic reticulum | | | B) | microtubules | | | C) | cytoplasm | | | D) | mitochondria | | | | | | Feedback: The cell's chemical processes take place in a semifluid material called the cytoplasm. This material provides an ideal environment for organelles because of its fluidity. | | 7 CORRECT | | This shows an example of endoplasmic reticulum. What is the significance of its structure? | | | A) | provides a location for DNA production | | | B) | helps decrease surface area | | | C) | allows selective permeability of cell membrane | | | D) | facilitates breakdown of chemical bonds | | | | | | Feedback: The pleats and folds of the endoplasmic reticulum provides a large surface area where cellular functions, such as breaking chemical bonds, can take place.
Within digestion lactose within milk is broken down by the enzyme lactase, without lactose having a complimentary specific shape to it lactase enzyme, some people are lactose intolerant. Thus it's very important that the enzyme lactase is able to fit with lactose. Shapes must also fit together within plants, in order for the plan to photosynthesis and survive competition and limiting factors.
Kirstie Javier AP Biology Period 4 November 14, 2011 Proteins Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. Some types of chemical bonds/ interactions are disulfide bonds, hydrogen bonds, ionic bonds, and hydrophobic interactions. Disulfide bonds form when two cytosine molecules join together to form a bond between their two sulfur atoms. Such bonds cross-link polypeptide chains or parts of chains. Because they are nonpolar covalent bonds, they are very strong bonds and not easily broken.
This is a form of passive transport across a membrane in which a transporter protein facilitates the movement of an impermeable membrane or ion across the plasma membrane down its concentration gradient. In facilitated diffusion, the direction of transport is always down a concentration gradient from one side of the membrane where the substrate concentration is high to the other side of the membrane where the concentration is lower. Facilitated diffusion is powered by the potential energy of a concentration gradient and does not require the expenditure of metabolic energy. The transport proteins responsible for these functions are referred to as uniporters. Amino acids, nucleosides, sugars, and other small molecules are often transported across membranes by uniporters.
Without these enzymes, our bodies cannot breakdown fructose into usable energy. A deficiency in aldolase B can be responsible for hereditary fructose intolerance by not allowing the second step of the process to happen. Hereditary fructose intolerance is a hereditary disorder caused by a genetic mutation. Because the enzyme adolase B is not functioning, the fructose 1 phosphate builds up in the liver and causes sequestration of F1P. This will lead to degradation of adenine nucleotides.
Lipid-soluble material moves through the membrane via the phospholipids; so they allow lipid-soluble substances to enter and leave the cell, prevent water-soluble substances entering and leaving the cell. Different kinds of membranes can contain phospholipids with different fatty acids, which affect the strength and flexibility of the membrane, and animal cell membranes. They also contain cholesterol which links the fatty acids together which stabilises and strengthens the membrane. The proteins in the membrane either sit on one of the layers (extrinsic proteins) or proteins that span the bilayer from one side to another (intrinsic proteins). The extrinsic proteins on the outside surface of the membrane either give support to the membrane or in conjunction with the glycolipids act as receptors for molecules such as hormones
This usually happens after a cell reaches its hayflick limit, the limit in number of times it can divide, and becomes senescent. However, if the P53 gene, a tumour suppressor gene, becomes mutated, these caspases may form with a different tertiary structure, meaning that the cell will not undergo apoptosis and will continue to divide uncontrollably, resulting in a tumour. Yet another occasion in which enzymes and substrates must fit together is during digestion, in which maltase is required to break substances down into simple carbohydrates required in respiration. If lactase is an
ENZYME worksheet 1. Label the diagram [pic] a. substrate b. active site c. enzyme d. products 2. Answer true of false to the following statements: ___T____ Enzymes interact with specific substrates ___F____ Enzymes change shape after a reaction occurs ___T____ Enzymes speed up reactions. ___F____ One enzyme can be used for many different types of chemical reactions. ___T____ Enzyme reactions can be slowed or halted using inhibitors.
Enzymes are a type of protein which speeds up the chemical reactions which occur within an organism by lowering the activation energy required to start the reaction. 6. Lock and Key- Only a specific substrate is able to fit in a particular enzymes active site as the substrate is believed to be a perfect fit for the active site. Induced Fit- When a substrate binds to an enzyme’s active site, the enzyme temporarily changes shape to accommodate the