Nat 5 Biology Unit 1 Cell Biology Verified Solution

Nat 5 Biology Unit 1 Cell Biology Verified Solutions Cell Wall ️️Maintains cell shape, made of cellulose in plant cells, bacteria and fungal cells have a different structure. Cell membrane ️️Is selectively permeable. It is made of proteins and phospholipids. It controls the entry and exit of substances in and out of the cell. Nucleus ️️Controls all of cell activities. It contains chromosomes which carry the genetic information. Cytoplasm ️️The site of chemical reactions. Contains enzymes. Vacuole ️️Membrane bound organelle containing cell sap. Mitochondria ️️Membrane bound organelle found in all cells except bacteria. They are the site of aerobic respiration and produce ATP. Cells with a high energy demand have more of these eg. muscle cell and sperm Chloroplast ️️Membrane bound organelle found in plant cells. Contain chlorophyll. The site of photosynthesis. Ribosome ️️Small almost spherical structure found in the cytoplasm of all cells. Site of protein synthesis. Concentration gradient ️️Different concentration of substances exciting between cells and their environment. Passive transport ️️The movement of substances along the concentration gradient, from an area of high concentration to an area of low concentration without using energy eg. Diffusion Osmosis ️️The movement of water molecules from an area of high concentration to an area of low concentration across a selectively permeable membrane. Active transport ️️The movement of substances from an area of low concentration to an an of high concentration. Requires energy. Cell division ️️Essential for growth and repair. The parent cell divides to produce two genetically identical cells. If becomes uncontrolled it can cause cancer. Mitosis ️️The division of the nucleus. Chromosomes ️️Thread-like structures found in the nucleus. Contain genetic information which controls cell activities. Made of DNA DNA ️️Made of two backbones to which bases are attached. The bases are A, C, T, G. The bases fit together in a particular way; A to T and C to G. This is called complementary base pairing. These strands twist and form a double-stranded helix. mRNA ️️Made in the nucleus by copying the genetic code for a gene and carries this copy to a ribosome. Protein ️️Made from amino acids. Joined together by polypeptide chains. Have a complex shape. The shape determines it's function. Enzymes ️️Biological catalysts which speed up vital chemical reactions. Hormones ️️Chemical messengers which help control the body's systems eg. Insulin Structural proteins ️️The building blocks which form cells, organs and tissues eg. Keratin. Antibodies ️️Produced by white blood cells to defend the body against viruses and unwanted bacteria. Receptors ️️Found in membranes of cells. Receive signals from molecules outside the cell and pass them across the membrane into the cell. Degradation reaction ️️Large substrate broken down into smaller product. Synthesis reaction ️️Small substrate built up to make a larger product. Genetic engineering ️️A technology that allows scientists to transfer DNA from one organism to another. Photosynthesis ️️A series of enzyme controlled reactions using the raw products, carbon dioxide and water to form glucose and oxygen. Green plants use this process to make their own food. Respiration ️️Chemical energy released by all cells through a series of enzyme controlled reactions. Glucose and oxygen to form carbon dioxide, water and ATP