Answer:
B.hydrogen bonding within polypeptide strands
Explanation:
Alpha helix is one of the secondary structures formed by polypeptide chains. It is formed when the backbone of a polypeptide is wound around a longitudinal axis. The side chains of the amino acids are oriented outwards. Alpha helix structure is stabilized by the formation of a maximum number of hydrogen bonds between the amino acids of the chain. The hydrogen atom linked to the electronegative nitrogen atom of a peptide bond form hydrogen bond with the electronegative carbonyl oxygen atom of the fourth amino acid.
In this way, every peptide bond except the ones present close to each end of the helix take part in hydrogen bonding and stabilize the structure.
Answer:
Explanation:
A protein molecule is made from a long chain of these amino acids, each linked to its neighbor through a covalent peptide bond (Figure 3-1). Proteins are therefore also known as polypeptides. Each type of protein has a unique sequence of amino acids, exactly the same from one molecule to the next.
Nicotine on direct application in humans causes irritation and burning sensation in the mouth and throat, increased salivation, nausea, abdominal pain, vomiting and diarrhea. Predominant immediate effects consist of increase in pulse rate and blood pressure. Nicotine also causes an increase in plasma free fatty acids, hyperglycemia, and an increase in the level of catecholamines in the blood. There is reduced coronary blood flow but an increased skeletal muscle blood flow. The increased rate of respiration causes hypothermia, a hypercoagulable state, decreases skin temperature, and increases the blood viscosity.
For amphetamine the immediate effects are quicker reaction times, feelings of energy/wakefulness, excitement, increased attentiveness and concentration, feelings of euphoria. Side effects of amphetamines can include heart palpitations, dry mouth, headache, hostility, nausea, cognitive impairment, severe anxiety, lack of appetite, teeth grinding, dizziness, increased heart rate, heart palpitations, rapid breathing rate, hypertension (high blood pressure), increased body temperature, erectile dysfunction, irregular heartbeat.
Cocaine causes a short-lived, intense high that is immediately followed by the opposite intense depression, edginess and a craving for more of the drug the side effects are Loss of appetite increased heart rate, blood pressure, body temperature, contracted blood vessels increased rate of breathing, dilated pupils, disturbed sleep patterns, nausea, hyperstimulation, bizarre, erratic, sometimes violent behavior hallucinations, hyperexcitability, irritability, tactile hallucination that creates the illusion of bugs burrowing under the skin, intense euphoria, anxiety and paranoia, depression, intense drug craving, panic and psychosis, convulsions, seizures and sudden death from high doses (even one time)
Answer:
While food chains and food webs show relationships between organisms, and energy pyramid quantifies the amount of energy transferred from one trophic level to the next, when one organism eats another, wherein approximately 10% of the energy available is retained and passed along.