> synapse: spaces between neurons, or between neurons and effectors > vesicles containing chemical neurotransmitters are located at the end of neuron axons Electrical Signals: > electrical impulses moving along the axon stimulate the release of neurotransmitters Chemical Signals: > neurotransmitters are released from the presynaptic neuron and diffuse across the synaptic cleft > neurotransmitters…
– obtained from bacterial cells where they act as an immune system, they digest foreign DNA molecules from viruses – molecular scissors that cut DNA at a specific base-pair sequence (the recognition site) – they scan DNA, stop at their recognition sites, then disrupt the phosphodiester bonds and the hydrogen bonds between nucleotides cutting a…
– cyclic process in the stroma that converts carbon dioxide into carbohydrate molecules – three phases: 1) carbon fixation, 2) reduction reaction, 3) RuBP regeneration Phase 1: Carbon Fixation – C02 added to RuBP -> unstable 6-carbon intermediate -> 2 3-carbon PGAs – required to occur three times, 3 CO2 + 3 RuBP -> 6…
Light Reactions: – require chlorophyll and take place in thykaloid membranes – absorb light energy and transfer it to ADP and NADP+ – energy is transferred to carbohydrate molecules in the Calvin cycle Carbon Fixation: – incorporate molecules of CO2(g) into organic molecules, such as glucose – require energy from ATP and NADPH – takes…
The nervous system is an elaborate communication system that functions to regulate the actions of your body to maintain the internal environment within safe limits Nerve Cells: Glial cells – non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin, and participate in signal transmission in the nervous system. Functions: – surround neurons and…
Mutations are errors made in the DNA sequence than can have negative side effects, no effect, or positive effects for an organism Point Mutations Mutations that occur at a certain point in the DNA Substitution – the replacement of one base in a DNA sequence by another base Deletion – the elimination of a base…
Thermoregulation is the maintenance of body temperature within a range that enables cells to function efficiently. Mammals, including humans, are endotherms, able to maintain a constant body temperature regardless of our surroundings. The hypothalamus acts as your body’s “thermostat”, detecting changes in body temperature and sending out messages to help restore the normal body temperature.…
The human body works best at 37°C, with a 0.1% blood sugar level and a blood pH level of 7.35 The external environment and making demands on your body do not always provide the ideal conditions for life Your body must adjust these variations to maintain a stable internal environment Homeostasis is a term used…
Living organisms must continually capture/acquire, store, and use energy to carry out the functions of life. Capturing/acquiring, storing and using energy are accomplished through cellular chemical processes. Cells are chemical machines that obey fundamental chemical and physical laws of nature. The sum of a cells chemical reactions is called metabolism. Energy Energy is the ability…
Function: ▪ synthesize and release hormones permitting them to act in concert and respond to changes in the body and maintain stability (homeostasis) ▪ Example organs – thyroid, pancreas (islets of Langerhans), adrenal glands, pituitary gland Tools: – hormones * chemicals released by cells in one part of the body that affect cells in other…
NADH and FADH2 carry electrons to the ETC Each become oxidized, losing two electrons to the ETC The Electron Transport Chain (ETC) Structure Located within the inner mitochondrial membrane Composed of various protein structures arranged in order of increasing electronegativity Ex. weakest electron attractor (NADH dehydrogenase) is at the beginning of the chain and the…
– O2 competes with CO2 for rubisco’s active site – rubisco catalyzes two reactions: 1) addition of carbon to RuBP; forms 2 PGA molecules (photosynthesis) 2) addition of oxygen to RuBP; forms 1 PGA and one glycolate (photorespiration) – photorespiration decreases the production of carbohydrates by removing PGA from the Calvin cycle – glycolate is…
Pancreas: > produces digestive enzymes and hormones > hormone producing cells are in the islets of Langerhans > islets contain beta (produce insulin hormone) and alpha cells (produce glucagon hormone) Insulin: > produced in beta cells > released when blood sugar level increases > cause muscle cells, the liver and other organs, to become permeable…
Carbohydrates are the first nutrient most organisms catabolise for energy, however, living things must metabolize other energy-rich nutrients to obtain energy in times of starvation Protein Catabolism – first digested into amino acids – amino groups are removed (deamination; amino group à ammonia [NH3]) – remaining portion of amino acid converted into various components of…
The quantity of energy associated with the formation of one mole of a substance from its elements (in their standard states). The standard states (at SATP) of most elements is solid, except for the gaseous diatomic molecules, H2, O2, N2, F2, Cl2, and the two liquid elements Hg and Br2. These energies can be looked…
The shape of a molecule determines many of its properties; For example: C4H10 is the formula for 2 separate molecules n-butane and isobutene Melting Point -138°C -159°C Boiling Point -0.5°C -12°C Enzymes—shape compatible with those molecules whose reactions they promote i.e. the enzyme sucrase breaks down the sugar molecule sucrose The shape of a…
Chemical reactions only take place when there are collisions between reactants Depends on: Number of collisions per unit time Fraction of collisions which are successful There is a relationship/pattern between reaction rate and the factors that affect it This pattern can only be determined empirically (through experimentation) Rate Law Empirical evidence supports that the reaction…
Enthalpy change is also known as heat of reaction, enthalpy of reaction, change in heat content. Enthalpy = total energy of a system It is impossible to measure the total kinetic and potential energy of a system, so instead we measure enthalpy change (using calorimeters). Enthalpy Change – is the energy absorbed from or released…
During a chemical reaction, reactant bonds need to be broken so that the atoms can rearrange to form the products. The kinetic energy of all the particles (the molecules, compounds, elements, atoms and ions) reacting is responsible for the breaking of these bonds. Remember, the temperature of the particles is a measure of the average…
Bioamplification is the accumulation of toxic pollutants in an animal. Toxins can be removed from the bodies of animals through sweating and urination, but these toxins need to be water soluble. DDT, DDE, PCBs, toxaphene, and the organic forms of mercury and arsenic do biomagnify in nature. These substances are consequently known as ‘persistent organic…