Unit 1 Test Macromolecules

Carbon has three properties that make it a special element. The first property of carbon is that it can join together, or bond, with up to four other elements. This means that carbon can form up to four bonds. The second property of carbon is that it can form bonds of different strength. Carbon can form single bonds, double bonds, or triple bonds with other elements. The last property of carbon is that it can form many different shapes. Carbon can bond with other elements to form rings, chains, or branched chains. Many building blocks (aka subunits/monomers) joined together make up organic molecules. The new large molecule that is formed is called a macromolecule. There are four examples of macromolecules: carbohydrates, proteins, lipids, and nucleic acids. For example the building block of carbohydrates is sugar the building block of lipids is three fatty acids and a glycerol the building block of protein is amino acids building block of nucleic acids is the nucleotide. When these building blocks (monomers) are joined together, they form a large molecule (polymer). Claim: Carbon is important for every living thing on Earth. Which 2 (TWO) of the following statements are evidence that supports this claim.

• Carbon is very flexible and can change shapes easily.
• Carbon can bond with up to 4 other elements.
• Carbon dissolves easily in water so it can soak into many living things
• Carbon is part of the building blocks of large polymers.

Identify the dependent variable in the following experiment: A scientist measures the growth of a plant as he changes the amount of light each plant receives.

• amount of sunlight
• amount of plants
• the scientist
• the plant growth

Identify the independent variable in the following experiment: A biologist is interested in the effects of global warming on aquatic animals. Therefore, he took samples of 10 urchins from the same site that all had different ocean temperatures. He then studied the thickness of each animal's shell.

• number of urchins
• ocean temperatures
• shell thickness
• urchin size

In a valid,controlled experiment, how many variables can be changed at a time?

• one
• two
• all variables
• three

The following statement is a hypothesis formed about marsh grass: If the amount of nitrogen marsh grass receives is increased, then the height of the grass will increase, because nitrogen is an essential nutrient needed for marsh grass to grow. What is the independent variable of the statement above?

• Height of grass
• Essential nutrient
• Amount of nitrogen
• Amount of growth

Adam is conducting a science experiment on the effect of different environments on plant growth. He put one plant in a closet and the other plant in a window at his house. He measured the growth of each plant weekly for six weeks. He then created a graph after he reviewed his data. What is the DEPENDENT variable in Adam's experiment?

• Total Growth of Plant.
• The Effect of Different Environments
• There is no independent variable
• Plant Environment
• The dark closet

Say you want to know whether caffeine affects your appetite. The presence/absence of a given amount of caffeine would be the __________ variable. How hungry you are would be the __________ variable.

• independent, dependent
• dependent, independent
• control, manipulated
• evidence, claim

A scientist analyzing an unknown substance has determined that it consists of carbon, hydrogen and oxygen. During experimentation, she determines that the substance is soluble in oil but not soluble in in water. Which of the following macromolecules is the unknown substance most likely to be?

• carbohydrate
• lipid
• protein
• nucleic acid

Which line represents a chemical reaction WITH an enzyme catalyst?

• blue line A
• dotted line
• red line B
• this isn't a reaction

Why do our cells need enzymes?

• they are needed as a reactant in a chemical reaction
• they are needed as a product in a chemical reaction
• chemical reactions would not occur without them
• chemical reactions would occur too slowly without them