Biochemistry/Macromelecules/Cell Structure

• Ions are atoms with an electrical charge
• A(n) molecule refers to two or more atoms held together by covalent bonds
• Covalent bond: when an electron pair is shared between two atoms
• Starch is a carbohydrate found in plants that is used for storage and energy
• Cellulose is a complex carbohydrate found in plants
• Which molecule is not a carbohydrate?

  (a)cellulose

  (b)starch

  (c)lipid

  (d)glycogen

  c
• Chitin forms the exoskeleton of arthropods and is a component of fungal cell walls
• Plant starch is composed of a mixture of 75 percent amylopectin and 25 percent amylose
• Two fatty acids are attached to the glycerol and make up the tails of the phospholipid
• A fat molecule is less soluble in water because it has three non-polar fatty acids and no polar or charged head like a phospholipid has
• hydrophilic and hydrophobic interactions with water hold phospholipids together in a bilayer formation
• Which one of these is an amino group?

  a

  
• Which one is a phosphate group?

  b

  
• Which one of these is a hydroxyl group?

  d

  
• Which one of these is a carboxyl group?

  f

  
• Which one of these is a carbonyl group?

  c

  
• Which of these functional groups is a characteristic of alcohol?

  d

  
• Which one of these functional groups acts as a base?

  a

  
• Which of these groups is characteristic of thiols?

  e

  
• Which of these groups plays a major role in energy transfer?

  b

  
• Which of these is a carbonyl group?

  c

  
• Which of functional groups listed below behaves as an acid?

  f

  
• Tertiary structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids
• Secondary structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain
• Primary structure is the sequence of amino acids in a protein
• Quaternary structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex
• This is an example of tertiary structure

  
• This is an example of primary structure

  
• This is an example of secondary structure

  
• This is an example of secondary structure

  
• This is an example of quaternary structure

  
• The cilia and flagella of eukaryotic cells are composed of microtubules
• Tight junctions form a barrier that prevents fluids from moving between cells
• The primary role of gap junctions is cell-to-cell communication
• The primary role of desmosomes (anchoring junctions) is to bind cells together
• Fimbriae are surface appendages that allow a bacterium to stick to a surface
• The DNA-containing region of this bacterial cell is indicated by the letter d

  
• The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter c