Download What are you made of?

What are you made of?
(2/23 – 2/24)
How food gets turned into... You!!!
Ummm... FOOD!!!
What parts of our food do we use?
• Only what our bodies can use
to make other things
• i.e. the 4 macromolecules
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Proteins
Carbohydrates
Lipids
Nucleic Acids
• We also absorb special
molecules used for special
jobs (vitamins and minerals)
Digestive system
• Food undergoes first steps of getting broken
down (by acids, enzymes, and bacteria)
• Sugars, proteins, nucleic acids absorbed into
circulatory system
• Lipids absorbed into the blood stream (e.g.
cholesterol) and the lymphatic system
Digestive system
Example: Cholesterol
• Begins at the mouth (chewing and saliva begin the
process of breaking down our food)
• Continues through the digestive system where
cholesterol gets absorbed into our blood stream
from the small intestines.
• Most cholesterol is absorbed from the blood into
the Liver
• About 25% of the cholesterol that we eat is
absorbed into other cells for use in the cell
membranes
Circulatory system
• Macromolecules either float through the
circulatory system or are carried by proteins
called lipoproteins
• Move through blood until there is a concentration
gradient or “need” for certain molecules by the
cells
• Less macromolecules in nearby cells than in the
blood causes a “need” for that molecule
• Cross into cells through diffusion or through
active transport
Cells – break it down!
• Lysosomes – organelle in cells that digests or
breaks the macromolecules down into their
subunits
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Proteins to amino acids
Lipids to fatty acids
Carbohydrates into simple sugars
Nucleic acids into nucleotides
Cells – hanging out, until...
• Most of these broken down macromolecules
“float” around in the cytoplasm until needed by
any of the many organelles doing countless jobs
• Genes located on your DNA (inside the nucleus)
get “turned on” by enzymes (a group of special
proteins)
• This marks the beginning of protein synthesis
Cells – the building begins!!! Phase one
1. DNA – unwinds and separates to expose the
“recipe” or sequence of bases
•
Has a unique language called bases: Adenine,
Thymine, Guanine, and Cytosine (A, T, G, C)
Cells – Protein synthesis!!! Phase 2
2. mRNA – latches onto the DNA bases and copies
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the “recipe” using a slightly different language,
then, moves out of the nucleus and into the
cytoplasm to one of the many ribosomes
RNA language is slightly different: Instead of using
Thymine, RNA uses Uracil (A, U, G, C)
Cells – Protein synthesis!!! Phase 3
3. tRNA – translates the recipe into amino acids.
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There are different tRNA for each of the 20
different amino acids
Same language as mRNA, but each tRNA only
has 3 letters and one amino acid
3 letters = codon
Happens in ribosomes
Cells – Protein synthesis!!! Phase 3
3. tRNA – translates the recipe into amino acids.
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There are different tRNA for each of the 20
different amino acids
Same language as mRNA, but each tRNA only
has 3 letters and one amino acid
3 letters = codon
Happens in ribosomes
Cells – Protein synthesis!!! Phase 4
4. Proteins!!! When the tRNA has translated all
of the mRNA, and each of the amino acids have
been joined together, your finished protein is
either used by the cell, or packaged and exported
in the ER or Golgi complex to other parts of the
body
Cells – Protein synthesis!!! Phase 4
4. Proteins!!! When the tRNA has translated all
of the mRNA, and each of the amino acids have
been joined together, your finished protein is
either used by the cell, or packaged and exported
in the ER or Golgi complex to other parts of the
body
Cells – Final touches...
• Once the amino acids have been joined
together to form the protein they get:
– sent off to Golgi Complex and/or ER for finishing
touches and to get packaged up and sent to their
“work site.”
– Or they get used immediately in the cell