| Homeostasis/ˌhəʊmiːəˈstɑːsiz/ |
Maintaining a relatively stable internal environment despite external or internal changes. |
| hypothalamus/ˌhaɪpəʊˈθælæməs/ |
A brain region that helps regulate homeostasis and links nervous control with hormonal signalling. |
| insulin/ˈɪnsjuːlɪn/ |
A hormone produced by pancreatic beta cells that helps lower blood glucose concentration. |
| Krebs cycle/krebz ˈsaɪkl/ |
A cycle of enzyme-controlled reactions that oxidises acetyl groups, releasing carbon dioxide and producing reduced coenzymes and a small amount of ATP or its equivalent. |
| lactate/ˈlækteɪt/ |
The ion formed from lactic acid, produced when pyruvate is reduced in lactate fermentation. |
| ligament |
A strong band of connective tissue joining bone to bone at a joint. |
| pituitary |
An endocrine gland at the base of the brain that releases hormones regulating several other glands and body processes. |
| plasmid/ˈplæzmɪd/ |
A usually circular DNA molecule that replicates separately from a cell’s main chromosome; engineered plasmids can carry inserted genes as vectors. |
| positive feedback/ˈpɒzɪtɪv ˈfiːdbæk/ |
A response that AMPLIFIES the original change, as in childbirth contractions. |
| proximal convoluted tubule/ˈprɒksɪml ˌkɒnvəˈluːtɪd ˈtjuːbjuːl/ |
The first twisted section of a kidney tubule, where useful substances such as glucose are reabsorbed. |
| Recombinant DNA/ˌriːˈkɒmbɪnənt ˌdiː en ˈeɪ/ |
DNA made by joining genetic material from different sources. |
| reflex arc/ˈriːfleks ɑːk/ |
The neural pathway connecting a receptor to an effector in a reflex response. |
| refractory period/rɪˈfræktəri ˈpɪərɪəd/ |
The interval after an action potential when another action potential is impossible or requires a stronger stimulus. |
| Respiratory quotient/rɪˈspɪrətəri ˈkwəʊʃənt/ |
The ratio of carbon dioxide produced to oxygen consumed during respiration, measured in comparable amounts over the same period. |
| restriction enzyme |
An enzyme cutting DNA at a specific base sequence. |
| saltatory conduction/ˈsɒltətəri kənˈdʌkʃn/ |
Transmission of an action potential along a myelinated axon by regeneration at successive nodes of Ranvier. |
| sino-atrial node |
The group of cells in the right atrium that normally initiates the heart's electrical rhythm. |
| sodium-potassium pump |
A membrane protein that uses ATP to move sodium ions out of a cell and potassium ions into it, maintaining their gradients. |
| sticky ends/ˈstɪki endz/ |
Short single-stranded DNA overhangs that can pair with complementary overhangs. |
| synapse/ˈsɪnæps/ |
A junction through which a neuron communicates with another cell, usually using a chemical transmitter. |
| tendon/ˈtendn/ |
A tough cord of collagen-rich tissue joining muscle to bone. |
| threshold/ˈθreʃəʊld/ |
A boundary value at which a specified effect begins or a decision changes. |
| transcription factor/trænˈskrɪpʃn ˈfæktə/ |
A protein that binds specific DNA sequences or interacts with transcription machinery to regulate gene expression. |
| urea/juːˈrɪə/ |
A nitrogen-containing compound formed from excess amino groups in mammals and excreted mainly in urine. |
