protein modification and gametes

• steps on protein modification 


  transcription of mRNA

  mRNA leaves nucleus

  proteins made on ribosomes enter rough ER

  protein moves through ER

  vesicles pinched off the rough ER contain the protein

  vesicles from the rough ER fuse to form sacs on golgi apparatus

  proteins and modified within the golgi apparatus/ carbohydrate chain is added

  vesicles pinched off golgi apparatus contain modified protein

  vesicles fuse with cell membrane releasing protein
• similarities between ovum and sperm 


  nucleus is haploid
• differences between ovum and sperm 


  sperm smaller than ovum

  ovum unable to move but sperm can move

  sperm has a tail

  ovum has zona pellucida