Bio Exam One
Which components form the structure of the plasma membrane?
A double layer of protiens
How does the diameter of a prokaryotic cell compare with the diameter of a eukaryotic cell?
A prokaryote has one-tenth the diameter of a eukaryote.
Which monomer units combine to form proteins?
Amino acids
Which vitamin is water soluble and cannot be synthesized by the body?
B
Which example is an element?
Calcium
Use the figure to answer the following question. Which substance uses a transport protein to pass through a plasma membrane?
Calcium ions
What molecule is composed of one or more sugars?
Carbohydrate
Which group of nutrients includes milk sugar (lactose)?
Carbohydrates
Which element is the basis for the macromolecules found in living things?
Carbon
Which feature is found in prokaryotic cells?
Cell wall
Which organelle is found in plant cells but not in animal cells?
Chloroplast
Which organelle performs photosynthesis?
Chloroplast
What protein fibers help form the framework of structural support for cells?
Cytoskeletal elements
Which feature is found in both prokaryotic and eukaryotic cells?
DNA
During diffusion, how do the solute molecules move?
Down a concentration gradient of solvent molecules
Which organelle is a network of membranes involved in the production of proteins?
Endoplasmic reticulum
How would amino acids and calcium ions from the bloodstream move across a plasma membrane?
Facilitated diffusion
Why is fiber important for a healthy diet?
Fiber helps maintain healthy cholesterol levels.
Which food would contain all essential amino acids?
Fish
What is the ability of living things to maintain a relatively constant internal environment?
Homeostasis
What type of chemical bond connects the complementary strands of a DNA molecule to each other?
Hydrogen bonds
What characteristic applies to the interior of a phospholipid bilayer?
Hydrophobic
Sodium chloride is composed of molecules that are stable when dry. In water, the atoms of the molecules separate from each other. What type of chemical bond holds the dry substance together?
Ionic bonds
Why is carbon often involved in chemical bonding?
It can form bonds with 4 other elements
Why is oxygen considered highly electronegative?
It pulls electrons toward itself.
Imagine a newly discovered biological molecule that is mostly hydrophobic in its structure. How would this new molecule be classified?
Lipid
Which organelle contains digestive enzymes that degrade macromolecules?
Lysosome
What are nutrients that the human body requires in large quantities?
Macronutrients
Which feature is present in all known living things?
Metabolic reactions
Why are minerals necessary micronutrients?
Minerals cannot be made by the body
Which organelle performs cellular respiration?
Mitochondrion
Which problem might result from decreases in a body's normal water level?
Muscle cramps
Which macromolecule has a sugar-phosphate backbone?
Nucleic acid
In which eukaryotic cell structure are ribosomes made?
Nucleolus
Which monomer units combine to form nucleic acids?
Nucleotides
What atoms may form a hydrogen bond?
One hydrogen atom and one partially negative atom
How are large substances moved during exocytosis?
Out of the cell
Which process involves the movement of molecules or atoms down a concentration gradient across plasma membranes?
Passive transport
What kind of molecule forms the bilayer found in cellular membranes?
Phospholipid
Some antibiotics disrupt bacterial phospholipids. Which cell component would be affected by such antibiotics?
Plasma membrane
Which chemical condition describes the electrons in a water molecule being shared unequally between the hydrogen and oxygen atoms?
Polar
Which substance is a micronutrient?
Potassium
What type of molecules, embedded in phospholipid bilayers, transport hydrophilic molecules into or out of the cell?
Protiens
What does "hydrophobic" mean?
Repelled by water
Which monomer units combine to form polysaccharides?
Sugars
How would the permeability of the phospholipid bilayer of plasma membranes be described?
The bilayer is always permeable to charged atoms and molecules.
Imagine a balloon is made from a membrane that's permeable to water but not sugar molecules. How would the concentration of sugar inside the balloon be affected if the balloon is filled with a 50% sugar solution and then placed in a beaker of water?
The concentration will decrease
What is diffusion?
The movement of particles from an area of high concentration to an area of low concentration.
What happens when the concentration of a solute is equal on both sides of a plasma membrane?
The particles will begin to move against the concentration gradient.
What is a function of antioxidants?
To decrease damage done to cells by free radicals
