Proteins are used to enable movement, provide structure and support, and carry out important chemical reactions inside the body. What is
needed in order for the human body to synthesize proteins?

A) A diet rich in amino acids
sufficient sunlight and water

B) sufficient sunlight and water

C) 1,200 calories of nutrients per day

D) minerals and fats in sufficient amounts

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.

i think the answer is a.keratin is the pigment responsible for skin color.