Question

water molecules are polar, with the
oxygen side being slightly positive and the hydrogen side being slightly negative.
oxygen and hydrogen sides being slightly positive.
oxygen and hydrogen sides being slightly negative.
oxygen side being slightly negative and the hydrogen side being slightly positive.

which of the following is not a function of proteins?
store and transmit heredity
help to fight disease
control the rate of reactions and regulate cell processes
build tissues such as bone and muscle

which organelle would you expect to find in plant cells but not animal cells?
mitochondrion
ribosome
chloroplast
smooth endoplasmic reticulum

Explanation:

First Question (Water Molecules' Polarity)

In a water molecule (\(H_2O\)), oxygen is more electronegative than hydrogen. Electronegativity determines the distribution of electron density. Oxygen attracts the shared electrons more, so it has a partial negative charge (\(\delta^-\)), and the hydrogen atoms have partial positive charges (\(\delta^+\)). So the oxygen side is slightly negative and the hydrogen side is slightly positive.

• Proteins can act as antibodies to fight disease (immune function), as enzymes to control reaction rates and regulate cell processes, and as structural components to build tissues (like collagen in bone, actin/myosin in muscle).
• Storing and transmitting heredity is the function of nucleic acids (DNA and RNA), not proteins.

• Mitochondria are present in both plant and animal cells (cellular respiration).
• Ribosomes are present in both (protein synthesis).
• Chloroplasts are found in plant cells (photosynthesis) and not in animal cells.
• Smooth endoplasmic reticulum is present in both (lipid synthesis, detoxification, etc.).

Answer:

D. oxygen side being slightly negative and the hydrogen side being slightly positive.

Second Question (Function of Proteins)