DNA & Protein Synthesis

Learning Target:Identify which key ideas about DNA and protein synthesis you still need to understand better

1. What is DNA and why is it important to all living things?

• Molecule that holds genetic information.• Blueprint for life, what makes you look the

way you look. Same for all living things.• Holds code for making proteins.

2. Identify 3 different functions of proteins in living things.

• Builds muscle.• Fight infections (antibodies)• Digest foods (enzymes)

3. Draw a simple diagram of a cell and label the following: nucleus, cytoplasm, cell membrane, DNA.

Good afternoon! Please get a computer and start logging on, and take out these this assignment…..

4. Draw a section of DNA that shows its double helix shape. Label four different nucleotide bases, showing which ones pair with which. What characteristic of DNA determines what protein is made from it?

A G C T

T C G

A

The order of the bases determines which amino acids are joined together to form a protein.

5. How are genes, chromosomes, and DNA related? Be sure to include a labeled diagram with your explanation.

• Chromosomes and genes are made of DNA.• Genes are sections of DNA.

6. Explain how proteins are made. Identify what happens in the nucleus of the cell, what happens in the cytoplasm, and what the following cell structures do: DNA, gene, mRNA, tRNA, amino acids, and ribosomes.

1. In the nucleus, a section of DNA (gene) is copied to make mRNA.2. mRNA goes out of the nucleus into the cytoplasm. tRNA brings

amino acids to the mRNA. Ribosomes join the amino acids together to make a protein molecule.

Protein Synthesis

TGCGGAG

7. If a DNA strand has a base sequence of ATTGCCCAG, what would the base sequence be on the opposite strand? What would the base sequence be on a strand of mRNA made from the ATTGCCCAG base sequence?

A T T G C CT A A C G G

U A A C G G

DNA

mRNA

C A GG T C

G U C

DNA has A, C, G, and T mRNA has A, C, G, and U

8. How are genes, proteins, and traits related to each other?

• Genes determine what proteins are made.• Proteins determine what traits you have.• Eye color is a trait determined by a protein.

Today’s task: “It’s In the Genes”, question 1

When finished: Log off computers and put back. Pick up a copy of “Mutations and Evolution”, and do questions 1-4…..

Videos: DNA and Protein Synthesis

http://www.youtube.com/watch?v=nHM4UUVHPQM

http://ed.ted.com/lessons/the-twisting-tale-of-dna-judith-hauck

https://www.youtube.com/watch?v=zwibgNGe4aY

9. Identify two environmental factors that can affect protein activity and explain how they change the protein molecule.

• Temperature, pH (acidity)• They change the shape of the protein molecule, meaning it can’t do its

job anymore.• Changing the shape of a key means it won’t work anymore.

Protein molecule denatured by heating

http://www.youtube.com/watch?v=v2-iY7ZoDOc

Today’s task: Invasive Crayfish, question 3

Testing tip• Copy the question into your answer to make

sure you’re answering the question.• For example…..– Q: “If one a DNA mutation happened in one of

your body cells, how could that affect you? How could it affect your offspring?”

– A: “If a DNA mutation happened in one of my body cells, it could…. It would not affect my offspring, because…….”

Protein shape makes a difference

Questions?