Learn more: Angina is chest pain or discomfort caused when your heart muscle doesn't get enough oxygen-rich blood. It may feel like pressure or squeezing in your chest. The discomfort also can occur in your shoulders, arms, neck, jaw, or back.Angina pain may even feel like indigestion.But, angina is not a disease.earn more: Angina is chest pain or discomfort caused when your heart muscle doesn't get enough oxygen-rich blood. It may feel like pressure or squeezing in your chest. The discomfort also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion.
Definition of leaven. 1a : a substance (such as yeast) used to produce fermentation in dough or a liquid; especially : sourdoughb : a material (such as baking powder) used to produce a gas that lightens dough or batter.
Chemical leavening agents allow bread dough to be prepared in minutes instead of hours. The chemical leavening agent, baking powder, is a mixture of baking soda, an alkaline ingredient; cream of tartar, an acidic ingredient; and a starch, such as cornstarch, which prevents clumping of the powder.