Midterm 2 semester 1 24-25

Protein
Synthesis

Proteins

●Proteins are polypeptides made up of amino acids

●Amino acids are linked by peptide bonds

●Gene expression: the process by which DNA
directs the synthesis of proteins

●Includes two stages: transcription and translation

●Occur in all organisms

Multiple Choice

Which property is shared by the cells of all living things?

• The cells contain DNA composed of adenine, thymine, guanine, and cytosine.

• The cells are surrounded by a phospholipid bilayer and a cell wall made of cellulose.

• The cells have chromosomes that are located inside a membrane-bound nucleus.

• The cells rely on mitochondria to carry out aerobic cellular respiration.

Protein Synthesis

●The process where DNA gets transcribed and translated into a protein

●“Synthesis” means to make something; protein synthesis=to make proteins

●Proteins are involved in transport, structure, acting as enzymes, and coding for traits

●Proteins are made by ribosomes

●Making proteins are essential for life

Multiple Choice

What is the correct order to make a protein?

• Protein, DNA, RNA

• RNA, DNA, Protein

• DNA, RNA, Protein

• Protein, RNA, DNA

Protein Synthesis

Protein synthesis
occurs in two major
steps

1.

Transcription

2.

Translation

1. Transcription

●Transcription is where a section of DNA
(genes) are transcribed “made” into
mRNA

Transcription steps:

1.RNA polymerase connects
complementary RNA bases to DNA

2.

RNA bases are bonded together to form
mRNA (messenger RNA)

●This process occurs in the NUCLEUS of
cells

Multiple Choice

Where does transcription take place?

• nucleus
• cytoplasm
• ribosome

Multiple Choice

What enzyme does transcription use?

• DNA polymerase

• ligase

• RNA polymerase

• helicase

Multiple Choice

The process by which the genetic code of DNA is copied into a strand of RNA is called

• translation
• transcription
• transformation
• replication

Types of RNA

1.mRNA- Messenger RNA

●Carries the “message” RNA complementary bases to DNA original strand

2.

rRNA- Ribosomal RNA

●Attaches to mRNA and helps with the pairing to tRNA (transfer amino acids)

3.

tRNA- Transfer RNA

●Pairs with mRNA message and transfers the amino acid it carries

Match

Match the following

• mRNA

• tRNA

• rRNA

Messenger RNA

Tranfer RNA

Ribsomoal RNA

• Messenger RNA

• Tranfer RNA

• Ribsomoal RNA

Types of RNA

3 bases-Codons

3 bases-Anticodon

Multiple Choice

Which RNA carries the message?

• mRNA

• rRNA

• tRNA

DNA Replication

●

DNA Synthesis= Making more DNA

●

In eukaryotic cells, occurs in the nucleus

●

In prokaryotic cells, occurs in the cytoplasm

●

DNA replication occurs BEFORE a cell divides(mitosis)

●

DNA replication occurs in S PHASE (interphase)

●*New (daughter) DNA strand is HALF of the original (parent)
strand

Where is DNA found in

Prokaryotes vs Eukaryotes?

Multiple Choice

Which organelle is DNA usually found in?

• cell membrane
• vacuole
• ribosome
• nucleus

The Cell Cycle: Part 1

1. Interphase (NON-dividing)
❏

G1 Phase

❏

S Phase

❏

G2 Phase

Match

What are the components of Interphase, and what happens in each phase?

• G2 Phase

• S Phase

• G1 Phase

Cell grows more and prepares to divide

DNA replication takes place

Cell grows; prepares for DNA replication

• Cell grows more and prepares to divide

• DNA replication takes place

• Cell grows; prepares for DNA replication

Interphase:(G1, S, G2)

●

Cell cycle STARTS here !!!

●

DNA is in its “normal” state

●

Longest phase of the cell cycle

●

Cell spends most of its life here

(resting phase).

●

Ensures DNA is replicated
properly before cell division
begins

Multiple Choice

If one strand of DNA has the sequence TTACCG, the sequence of complementary strand of the same molecule will be

• AATGGC
• TTACCG
• AACGGC
• AATGGG

Interphase: S Phase

●

DNA replicates (makes a copy of itself)

●

DNA Synthesis

Multiple Choice

DNA is replicated during ______ of the cell cycle.

• G1 Phase

• S Phase

• G2 Phase

• G0 Phase

Interphase: S Phase

Semi-conservative model of dna replication during the s
phase

Notice it looks like a zipper unzipping!

Cancer

● Cancer is…a disruption/failure of the cell cycle,

causing uncontrolled/unregulated cell growth

● Cells are…supposed to go to G0, but they don’t
● They instead replicate with damaged DNA
● Cancer cells grow more unevenly than healthy cells

○ Clump to form tumors

Multiple Choice

Uncontrolled cell division which usually leads to tumors and disease is called:

• Metaphase

• Cytokinesis

• Cancer

• Diabetes

Multiple Select

Which of the following are characteristics of Cancer? select all that apply

• It divides uncontrollably

• It needs a host to reproduce

• It forms tumors

• It is a failure of the cell cycle

Components of

DNA

Multiple Choice

In Texas Longhorn cattle, coat coloration is an inherited trait. What is the genetic basis of

coat-color variation in Texas Longhorn cattle?

• Differences in the nucleotide sequences of genes

• Differences in the numbers of chromosomes in cells

• Differences in the diets of individual cattle

• Differences in the environmental conditions of different geographic areas

Multiple Choice

Which statements best compare the function of an ATP molecule to a DNA molecule?

• ATP carries and transmits the genetic information of organisms.

  DNA serves as a biological catalyst that speeds up the rate of chemical reactions

• ATP provides energy for chemical reactions in the cell.

  DNA carries and transmits the genetic information of organisms

• ATP serves as a biological catalyst that speeds up the rate of chemical reactions.

  DNA acts as a structural sugar in the cell walls of plants.

• ATP acts as a structural sugar in the cell walls of plants.

  DNA provides energy for chemical reactions in the cell.

DNA (Deoxyribose Nucleic Acid)

●DNA is the blueprint for the traits of an organism

●DNA is found in the nucleus of cells (eukaryotes) or floating around in the
cytoplasm (prokaryotes)

●DNA has a double helix structure/shape

(looks like a twisted ladder)

●DNA is doublestranded

●DNA is a nucleic acid

●DNA’s monomer: nucleotide

●Elements present in DNA carbon, hydrogen, oxygen, nitrogen,
phosphorus/phosphate

Multiple Choice

DNA is shaped in a:

• double helix

• tightly packed swirl

• twisted ladder

• nucleotide

Multiple Choice

DNA stands for

• Deoxyribose Nucleic Acid

• Dunder Nucleic Acid

• Dopamine Nucleic Acid

• Deciduous Nucleic Acid

DNA (Deoxyribose Nucleic Acid)

●DNA monomer: Nucleotide

●Many nucleotides make a strand of
DNA

Parts of a DNA nucleotide

1.

Deoxyribose (sugar)

2.

Phosphate

3.

Nitrogen base (Adenine, Thymine, Guanine,
cytosine)

***THE SEQUENCE/ORDER OF

NUCLEOTIDES/BASES DETERMINES SPECIFIC

TRAITS (proteins/polypeptides)

Multiple Choice

What is this a picture of?

• nucleotide

• DNA strand

• chromosome

• gene

Multiple Choice

What are the parts of a nucleotide?

• phosphate, sugar, base

• A, T, G, C

• Nucleic Acids

• two base pairs connected

Multiple Choice

The order of the nitrogenous bases in DNA determines:

• the genetic code

• the presence of polarity

• the presence of a hydrogen bond

• if there is a fifth nitrogen base

RNA (Ribonucleic acid)

●RNA nucleotide is the building block for RNA

●RNA is Single stranded

RNA nucleotide

1.

Ribose (sugar)

2.

Phosphate

3.

Nitrogen base (Adenine, Guanine, Cytosine,
URACIL)

Multiple Choice

The following picture must be

• DNA because it's double stranded
• RNA because it's single stranded
• DNA because it's single stranded
• RNA because it's double stranded

Multiple Choice

RNA has what base that is instead of thymine?

• guanine

• adenine

• thymine

• uracil

Sugar-Phosphate Backbone

● Deoxyribose (sugar) and

phosphate make the backbone
of the DNA molecules

● “Sides of the ladder”

Multiple Choice

The 'backbone' or 'sides of the ladder' of the DNA strand is made of:

• phosphate and sugar

• phosphate only

• phosphate and base

• sugar and base

Nitrogenous Bases

●Complementary nitrogenous bases

●Bases are attached to the sugars !!

●Adenine goes with Thymine (A-T)

●Guanine goes with Cytosine (G-C)

●(in RNA Adenine goes with Uracil (A-U)

●Hydrogen bonds hold these bases together

*THE SEQUENCE/ORDER OF THE NITROGENOUS

BASES/NUCLEOTIDES DETERMINES SPECIFIC TRAITS

(PROTEINS/POLYPEPTIDES) OF AN ORGANISM

Multiple Choice

Hydrogen bonds occur:

• on the ribbon (between the sugar)

• between the bases

• only between A & T

• only between G & C

Multiple Choice

Which of these identifies the part of the DNA segment labeled X?

• Nucleotide

• Phosphate Group

• Hydrogen Bond

• Deoxyribose

Multiple Choice

What part of a nucleotide accounts for the genetic variation between individuals?

• phosphate
• nitrogenous base
• deoxyribose
• sugar

DNA Replication

●Template (original)strand is used to make a COMPLEMENTARY (new) strand

●(A goes with T), (G goes with C)

●Template strand (original): Goes from 5’ to 3’

●New (complementary) strand: Goes from 3’ to 5’

Template (original) strand:
5’-A T G C A A C T G C G T A C T G A C C T A G T T A G-3’
| | | | | | | | | | | | | | | | | | | | | | | | | |
3’ T A C G T T G A C G C A T G A C T G G A T C A A T C-5’
New (complementary) strand

Multiple Choice

Which shows the correct complementary base pairing for DNA?

• C-A, T-G

• A-G, C-T

• C-G, U-A

• A-T, G-C

Multiple Choice

Which sequence of DNA bases would pair with this partial strand
CAT TCA CTG

• ATG TGA CAG
• TAC ACT GTC
• GTA AGT GAC
• CAT TCA CTG

Multiple Select

What two things are the product (end result) of photosynthesis?

• chloroplast

• glucose

• oxygen

• carbon dioxide

Multiple Choice

Where do plants get the energy for photosynthesis to take place?

• nutrients in the soil

• the sun

• chlorophyll

• bee pollination

Multiple Choice

What are the products of photosynthesis?

• water and carbon dioxide
• oxygen and glucose
• oxygen and carbon dioxide
• oxygen and water

Multiple Choice

Which of the following is the correct equation for PHOTOSYNTHESIS?

• CO₂ + light + H₂O --> O₂ + Sugar
• CO₂ + sugar + H₂O --> O₂ + light
• _O2 + light + H₂O --> CO₂ + Sugar
• CO₂ + O₂ + H₂O --> Light+ Sugar

Multiple Choice

•The organelle responsible for photosynthesis:

• Vacuole

• Chloroplast

• nuclear membrane

• mitochondria

• Cytoplasm

Multiple Choice

What is the correct equation for cellular respiration?

• oxygen + sugar -> carbon dioxide + water + Energy

• carbon dioxide + sugar + Energy -> carbon dioxide + water

• carbon dioxide + water -> oxygen + sugar + Energy

• carbon dioxide + water + Energy -> oxygen + sugar