Hannah is boiling water in a glass hes kettle. She notices bubbles forming on the bottom of the kettle that rude to the up and wonders what is in the bubbles. She asks her family what they think and this is what they say

Dad: they are bubbles of heat

Calvin: the bubbles are filled with air

Grandma: the bubbles are an invisible form of water

Mom: they are empty

Lucy: the bubbles contain oxygen and hydrogen that separated from the water

Which person do you most agree with and why?

(Answer in full and complete sentences)

Name the type of chemical that speeds up digestion

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

14. which of the following codons code for threonine? a. ucg b. ugu c. cga d. aca