Warm-Up: Fill in the blanks with this word bank:

• Nucleus

• Three

• Amino acids

• Deoxyribose nucleic acid

• Gene

• Eukaryotic

• Codons

• Transcription

• Nucleotides

• Protein

• Ribosomes

• Translation

Check your answers:

1. DNA stands for ___________________________.

2. DNA is contained within a __________________ cell’s _________________________.

3. DNA is composed of ______________________ that come in four different types, C, G, T, and A.

4. A section of DNA that codes for a certain trait is called a _________________.

5. Each gene contains the genetic information to create one __________________________.

Deoxyribose Nucleic Acid

EukaryoticNucleus

Nucleotides

Gene

Protein

Check your answers:6. Genetic instructions in the DNA are changed to mRNA during ________________________ in the nucleus.

7. The instructions from mRNA are brought to _______________ in the cytoplasm to synthesize proteins.

8. mRNA and tRNA work together at ribosomes to turn _________________ into proteins.

9. The process of changing mRNA instructions into proteins is called ______________________________.

10. Life’s diversity is possible because RNA uses groups of _____ nucleotides. These groups are called ______________.

Transcription

Ribosomes

Amino Acids

Translation

3Codons

DNA Practice Problem:

Organism Percentage of each type of base

Adenine Thymine Cytosine Guanine

Human 31 19

Cow 28 22

Wheat 27

The proportions of the bases are consistent within a species; however they do vary between species. Using the base-pair rules (%C = %G and %A = % T), complete the following table to show the percentage of each type of base in the five different organisms.

DNA Practice Problem:

Organism Percentage of each type of base

Adenine Thymine Cytosine Guanine

Human 31 19

Cow 28 22

Wheat 27

The proportions of the bases are consistent within a species; however they do vary between species. Using the base-pair rules (%C = %G and %A = % T), complete the following table to show the percentage of each type of base in the five different organisms.

1931

2228

27 23 23

DNA Replication

1. DNA replication is the process that creates two identical sets of DNA from one original set of DNA

2. DNA has to replicated because all cells come from cells that already exist, so DNA has to be created from previous existing DNA also. To make sure both “new” cells have DNA, a second set of DNA has to be made.

DNA Replication

3. DNA has to go through a few steps to be copied.

1. DNA is straightened and “unzipped” by an enzyme

2. This creates two template strands that free nucleotide bases can pair with

3. More enzymes connect the new base pairs intoa strand and close up the new DNA

DNA has to be unzipped before replication so that new nucleotide bases can pair with each template strand

Dang

4. The darker blue is the original DNA, the light blue are new nucleotides. Look at

how each new “daughter” DNA is half old and half new.

DNA Replication

5. DNA is important since it makes cells work correctly. To limit mistakes, DNA replication is a semi-conservative process.

Because DNA starts with two strands, by splitting it in half and then adding new nucleotides to each strand, the chances of a mistake are limited.

DNA Replication Questions

1. Examine the model. Number the steps below in order to describe the replication of DNA in a cell.

______ Hydrogen bonds between nucleotides form.

______ Hydrogen bonds between nucleotides break.

______ Strands of DNA separate.

______ Free nucleotides are attracted to exposed bases on the loose strands of DNA.

DNA Replication Questions

1. Examine the model. Number the steps below in order to describe the replication of DNA in a cell.

______ Hydrogen bonds between nucleotides form.

______ Hydrogen bonds between nucleotides break.

______ Strands of DNA separate.

______ Free nucleotides are attracted to exposed bases on the loose strands of DNA.

1

2

3

4

DNA Replication Questions2. Locate the DNA helicase on Model 2.

a. What type of biological molecule is DNA helicase?_______________

b. What is the role of DNA helicase in the replication of DNA? ______________________________________

3. What rule is used to join the free nucleotides to the exposed bases of the DNA?

Helicase is an enzyme

Helicase splits the original DNA so it can replicate

Adenine will always bind with thymine and cytosine will always bind with guanine.

DNA Replication Questions4. This type of replication is called semi-conservative replication. Considering the meaning of these words (semi—half; conserve—to keep), explain why DNA replication is called semi-conservative.

Each new daughter DNA kept half of the original DNA, while half of it is new.

2009-2010

Mutations

Changes to DNA

Mutations

1. Changes to DNA are called mutations

– change the DNA

– changes the mRNA

– may change protein

– may change trait

DNA TACGCACATTTACGTACG

mRNA AUGCGUGUAAAUGCAUGC

aa aa aa aa aa aa aaprotein

trait

Types of mutations

• Changes to the letters (A,C,T,G bases) in the DNA

– point mutation

• change to ONE letter (base) in the DNA

• may cause change to protein, may not

– frameshift mutation

• addition or deletion of a new letter (base) in the DNA sequence

• both of these shift the DNA so it changes how the codons are read

• big changes to protein!

An example of types of mutations in words

Use this chart to help you answer the questions on the back:

The first couple have been done as examples:

A U G U G G A A C C G C U G C U G A

Start Trp Asn Arg Cys Stop

A U G U A G A A C C G C U G C U G A

Start, StopYes

Point Mutation

A U G C U A G A A C C G C U G C U G AStart, Leu, Glu, Pro, Leu, Leu, …

Yes

Frameshift Mutation

Finish the rest of the back of this paper, including the bottom about sickle cell anemia. A condition that affects some people’s red

blood cells:

After you finish the worksheet, check your answers with the answer key up

front.

Once you check your answers, click to the next slide.

Socrative Quiz Time• Get a Chromebook, go to Socrative, click student

login and type in room number 336487

• Type in your name in the order “Last name, First name”

• The quiz is open notes, and you can take it up to two (2) times

• Finish the Protein Synthesis Webquest when you finish.