Exam 2 Flashcards
Which enzyme unwraps the double helix?
Helicase
The double helix of DNA is wrapped about 1 & 3/4 times around which of these components?
Nucleosome
During DNA replication int he lagging strand there is production of this component?
Okazaki fragment
RNA is double stranded
False
Draw the sugar in DNA & label the carbons as discussed in the lecture. Then circle the carbon that is different in RNA.
Assume you have a eukaryotic cell with three chromosomes within it. How many 5’ ends would there be?
Gap 1= 6, Gap 2= 12
During mRNA maturation what is the name of the part of the mRNA that is removed?
Intron
How many “stop” codons exist?
Three
How many hydrogen bonds are there between an A and its paired nucleotide?
Two
List one type of post-translational modification
Phosphorylation
RNA synthesis, also called RNA transcription occurs in three phases. Listen them from beginning to end in order.
Initiation, Elongation, Termination
Replication of DNA is semi-conservative
True
In the ribosome, what is the name of the bond that links one amino acid to the next?
Peptide bond
Protein synthesis changes from the language of ___ to the language of ____.
nucleotides, amino acids
Strands of the backbone of DNA are parallel?
False
There are two types of protein synthesis in eukaryotic cells. These two types can be distinguished because the polyribosome is either ___ or ____.
free, membrane-bound
Which strand is produced more rapidly?
Leading strand
During DNA replication is greatly reduced by enzymes that proof read the newly replicated DNA.
True
Which nucleotide is different in RNA compared to DNA?
Uridine replaces Thymidine
In DNA, what does the nucleotide labeled as A pair with?
T (Thymidine)
List the two basic categories of nitrogenous bases in nucleic acids.
Pyrimidines, Purines
Which sugar is present in RNA?
ribose
DNA replication in eukaryotes is sped up by multiple origins of replication.
True
In the ribosome, what pairs with the codon?
Anticodon
The DNA polymerase that replicates the parental strand of DNA reads the parental DNA from 5’ to 3” and makes a new DNA strand from 3’ to 5’.
False
In the lagging strand, the DNA is read from the parental DNA’s 3’ to 5’ end.
True
For DNA Polymerase III to work which of these components has to act first?
Primase
Uridine is a nucleotide in DNA.
False
The genetic code for the conversion of mRNA codons to proteins has redundancy.
True
In eukaryotic cells the start codon for protein synthesis is _____
Methionine
Which enzyme is used first to permit DNA polymerase III to begin replicating the 3’ strand?
Primase
The Calvin-Benson cycle takes in ____ and _____ from the light reaction and also ____ ____ to make carbohydrates.
ATP, NADPH+ H+
Carbon Dioxide
List three items required for photosynthesis to occur.
H2O, CO2, light
The antenna system is in the ____ membranes
Thylakoid
The most abundant protein in the world is called _____.
Rubisco
The light reactions produce ____ and ____ and this process also results in the release of ____.
ATP, NADPH+ H+
Oxygen
Glycolysis requires the investment of two ___ in order to obtain a gross output of four ___.
ATPs, ATPs
Specifically where in a cell does the citric acid/Kreb’s cycle occur?
Mitochondrial matrix
The cell does not need ATP to survive.
False
The citric acid/Kreb’s cycle breaks down carbohydrates into CO2.
True
Specifically in a cell where does Glycolysis occur?
Cytoplasm
Where is carbon dioxide produced?
Mitochondrial matrix
FADH2 results as one of the products of the citric acid cycle.
True
Does gravity have a role in some part of the lymphatic fluid flow back to the circulatory system?
Yes
Any cell can present an antigen on a class I major histocompatibility complex (MHC) protein.
True
There are times when the spleen can be considered to be the primary lymph node.
True
B and T cells are called lymphocytes.
True
Lymphatic tissue is composed of the following five components. List them.
Bone Marrow, Thymus, Spleen, Lymph Nodes, and Lymphatic Ducts
In the lecture we discussed normal flora, this refers to:
Bacteria & fungi on the surface of the skin that compete against pathogens.
When a B cell is shown an antigen on a class II major histocompatibility complex (MHC) protein it will go through ____ _____ and B cells subsequently can become ______ and/or ______ ______.
Blast transformation, Plasma cells, Memory cells.
You should have your appendix removed whenever possible.
False
Having a fever of 100 F can help you fight off infections.
True
How does lymph fluid return from the legs to the circulatory system?
The left lymphatic duct drains excess fluid from the legs and uses the body’s muscles to help in pushing the fluid back up through the vessels using a one-way system in the lymphatic duct that prevents backflow of fluid (preventing it from coming back down with gravity).
Bone marrow is a site where mature immune cells are found.
False
Red blood cells originate from the bone marrow.
True
When immune cells mature and can recognize trans-membrane proteins indicating “self,” this is called _____.
Tolerance
Red blood cells are a part of the immune system.
False
Natural killer cells are part of the specific immune system.
False
Lymph nodes are a place where cells of the immune system accumulate and share information.
True
In 1 mL of blood, there are 1.5 million white blood cells.
False
Memory cells “remember: the antigen and make a faster and greater response the next time the antigen is encountered.
true
If a macrophage endocytoses (eats) an antigen it can digest it and present it on a ____ Major histocompatibility complex protein to a _____.
Class II, Helper T cell
A bacterium coated by antibodies is a signal that a macrophage should endocytose (eat) it.
True
Inflammation is caused by an increase in blood supply due to _____ released by some cells of the immune system.
Histamine
Any cell can present an antigen on a class II major histocompatibility complex (MHC) protein.
False
The humoral immune system involves cells in the immune system.
True
Memory cells :remember: the antigen and make a faster and greater response the next time the antigen is encountered.
True
A bacterium coated by antibodies is a signal that a macrophage should endocytose (eat) it.
True
Mast cells release histamine.
True
Adhering junctions are based on two different types of cytoskeleton filament systems. Name those systems.
The actin filament system & the Intermediate filament system.
The molecular seal that serves as the barrier is called a ____ _____. While this is a good barrier, such barriers are not very strong and must be underlined by ____ ______.
Tight junction, Adhering junctions.
Epithelial cells serve as a barrier to prevent non-specific movement of chemicals from one side of the epithelium to the other side.
True
90% of absorption in the intestine occurs where?
The jejunum and the ileum
Write a few sentences to distinguish between digestion and absorption.
Digestion is the breaking down of food into smaller “chunks,” and does not involve nutrient absorption. Absorption is the actual taking in of nutrients into the body.
If something is called a vitamin, it cannot be made by the organism and must be taken in as part of diet.
True
Name the main enzyme in the stomach
pepsin
When glucose is taken in by the digestive track and enters your blood, cells are triggered to take in the glucose by what mechanism?
The release of insulin from the pancreas
Think about feedback loops. What triggers the gall bladder to secrete bile?
cholecystokinin (CCK)
When amino acids are acquired by food because your body can’t make them they are called ____ _____ ______
Essential amino acids
List the order in which storage compounds are utilized if there is no intake of food
glycogen, fat, protein
The esophagus has two distinct muscles that close off the tube. What are these called?
Circular muscles and longitudinal muscles.
What is bile made from? And how does oatmeal reduce cholesterol levels?
Cholesterol. Oatmeal binds to bile and lowers cholesterol by decreasing its absorption in the ileum.
Name the sphincter that separates the stomach from the small intestine
The Pyloric Sphincter
How does the pancreas neutralize the pH of the chyme that comes from the stomach?
The pancreas produces a secretion rich in bicarbonate ions which help the neutralize the pH of the chyme in the stomach.
Draw concentric circles and label the four layers of the gut. Also label the hole at the innermost circle. List what is in these four layers.
In what way is the making of a primary lysosome similar to the enzymes delivered by the pancreas?
They both break down sugars, fatty acids, nucleic acids & proteins.
Vitamin K cannot be made by the cells of your body. Where is it made?
In the colon (large intestine), made by bacteria.
List the layers of the digestive track covered by a thick layer of mucous.
mucosa layer, submucosa layer
The digestive track begins with the ______ and the first enzyme added is _____.
Mouth, amylase
