Nature of Matter
What is the basic unit of matter?
An atom.
Which part of a water molecule is slightly negative?
The oxygen side.
Which macromolecule is the main source of quick energy and includes sugars and starches?
Carbohydrates
Is a substance with a pH of 3 acidic, neutral, or basic?
Acidic
What is the energy needed to start a chemical reaction called?
Activation energy.
Which subatomic particle has a positive charge?
A proton.
What is the attraction between the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another called?
A hydrogen bond
Which macromolecule is made of amino acids joined by peptide bonds?
Proteins
What pH is neutral, and what does neutral water contain in equal amounts?
pH 7
equal amounts of hydrogen ions and hydroxide ions
What is the name of the starting substances in a chemical reaction?
Reactants.
One carbon atom has 6 protons and 8 neutrons. Another carbon atom has 6 protons and 6 neutrons. What is the name for this?
Isotope
Water molecules stick to each other and form droplets. What property is this?
Cohesion
A student needs to identify a molecule of amino acids. Which macromolecule should they choose?
A protein
A solution has a pH of 11. Is it acidic or basic, and which ions are more present?
It is basic and has more OH⁻ ions.
What is the name of the substances formed by a chemical reaction?
Products
A neutral atom loses an electron. What happens to its charge, and why?
It becomes positively charged because it has more protons than electrons.
Water sticks to the walls of a plant's tiny tubes. What property is this?
Adhesion
A food contains starch. Which macromolecule group does the starch belong to?
Carbohydrates
What does an acid release into a solution?
Hydrogen ions (H⁺).
How does an enzyme change the activation energy needed for a reaction?
Reveal answerBack to board
It lowers the activation energy.
What is the difference between ionic and covalent bonds?
Ionic - transfer electrons
Covalent - share electrons
Why do oceans help keep nearby temperatures from changing quickly?
Water has high heat capacity, so its temperature changes slowly.
What are the building blocks for each:
Carbs, nucleic acids, proteins, lipids
monosaccharides, nucleotides, amino acids, glycerol + fatty acids
Why are buffers important in the human body?
They help prevent sudden pH changes so conditions remain stable for cells and their reactions.
On an energy graph, how should the curve with an enzyme compare with the curve without an enzyme (above or below)? What stays the same?
The curve with an enzyme has a lower peak; the reactants and products start and end at the same energy levels.