proteins

• >50 amino acids
• biological machines

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what they can do

enzymes

speed up chemical reactions

• digestion
• metabolism
• dna replication
• energy production
  • atp
  • creatine kinase

structural

• build and maintain structures
  • skin
  • hair
  • nails
  • muscles

transport

• move molecules around the body
  • oxygen

signaling

• cell communication
  • beta-receptors
  • insulin
  • hormones
  • neurotransmitters

immune

• immune system defense

contractile

• store nutrients and other molecules

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