Bio exam

Saturated fatty acids can exist in cis and trans configuration but unsaturated fatty acids cannot.

False

LDL is good cholesterol and HDL is bad cholesterol

False

Waxes are a class of lipids that constitute of long chain alcohols esterified to long. chain fatty acids. This is different from triglycerides where fatty acids are esterified with glycerol back bone

true

Triglycerides have fatty acids are esterified with glycerol back bone, and phospholipids are triglyceride where one fatty acid chain is replaced by phosphate group.

true

Facilitated diffusion is an example of active transport

False

ATP is required for an Active transport.

true

What may a nucleotide of DNA contain?

deoxyribose, thymine, and a phosphate group

What is found in RNA that is not in DNA?

ribose and uracil

Where is the largest amount of DNA found in a eukaryotic cell?

in the nucleus

What are the building blocks of nucleic acids?

nucleotides

If DNA of a particular species was analyzed and it was found that it contains 23% T, what would be the percentage of G?

27%

The experiments by Hershey and Chase helped confirm that DNA was the hereditary material on the basis of the finding of what?

Radioactive phosphorus was found in the cell.

What are some differences between DNA and RNA?

DNA contains deoxyribose and thymine, while RNA contains ribose and uracil.

Which molecule carries information in a form that is inherited from one generation to another?

Hereditary information is stored in DNA.

What do RNA and DNA have in common?

Both contain four different nucleotides.

Meselson and Stahl's experiments proved that DNA replicates by which mode?

Semi-conservative

Explain how the components of DNA fit together.

involves phoshodiester bond, glycosidic bond and hydrogen bond

The bond between sugar molecule and Nitrogenous base is called glycosidic linkage in DNA but not in RNA

False

Phosphoric acid molecule forms a bridge between 5' carbon of one nucleotide with 3' carbon of another molecule. This establishes 5' to 3' directionality in the DNA synthesis, but what is this bond or interactions called

Phosphodiester bond

RNA is single stranded, has uracil in place of thymine, contains ribose sugar and not deoxyribose sugar and is of following three types, mRNA, tRNA and rRNA.

true

RNA is of three types mRNA, tRNA and rRNA. Over the last two decades RNA has been found to be of further types; miRNA (micro RNA) and siRNA (small interfering RNA). miRNA are usually 20 nucleotide long and have biological functions. siRNA are again small RNA molecules but they interfere with metabolic processes. Do you think in coming years these RNA will prove to be biologically more involved than we know now.

yes

1. DNA
2. RNA
3. nucleotide
4. nucleoside
5. Hershey and Chase
6. Watson and Crick

1. Double stranded
2. ribose sugar
3. sugar, base, phosphate
4. sugar, base
5. DNA is genetic material
6. DNA structure

An example of a monosaccharide is

fructose, glucose, galactose

Cellulose and starch are examples of:

polysaccharides

Lactose is a disaccharide formed by the formation of a ___- bond between glucose and

glycosidic; galactose

The monomers that make up proteins are called

amino acids

The a-helix and the -pleated sheet are part of which protein structure?

Secondary

Protein syntheses is directional, occurs from C to N terminal

False

What is the hierarchy in protein structure?

primary, secondary, tertiary, quaternary

In sickle cell hemoglobin, the glutamate is replaced by a valine. This change is termed mutation.

true

Chaperones maintain functional proteins (proteome) in living organisms and prevents diseases

true

Cellulose in a branched polymer while amylopectin is branches and glycogen is highly linear polymer of monosaccharides.

true

What is the normal, and pre-diabetic level of fasting blood sugar in humans

100 mg/dL; 100-125 mg/dL

Lipid bilayer means an arrangement where to layers of lipid molecules are arranged in such a way that polar heads make the outer boundary and hydrophobic tails are arranged on inner side.

true

1. proteins
2. carbohydrates
3. Nucelic acids
4. Beta-sheet
5. Membrane
6. Cholesterol

1. amino acid
2. Monosaccharides
3. Nucleotide
4. hydrogen bonding
5. Phospholipids
6. steriod

Cellulose and starch are examples of

polysaccharides

what happens to the membrane of a vesicle after exocytosis?

it leaves the cell

Glycogen and starch are storage polysaccharides while cellulose is a structural polysaccharide

true

Plasma membrane îs a sphere of lipid bilayer that envelopes nucleoplasm.

False

cellulose in a linear polymer while amylopectin is branches and glycogen is highly branched polymer of monosaccharides.

true

Cellulose is called a dietary fiber because it cannot be digested by the body. However, in bacteria Symbiotic bacteria help them digest cellulose.

true

Bacterial plasma membranes is rich in phosphatidylethanolamine and Mitochondrial membranes are rich in phosphatidy|serine

true

Hydrogen bond is as strong as covalent bond

false

Water is a polar molecule, methane is non-polar and NaCl is ionic

true

The fluid mosaic model of the plasma membrane describes the plasma membrane as a combination of phospholipids, cholesterol, and proteins which can move with respect to each other.

true

RNA is a polymer of

ribonucleotides

Passive transport across the membrane could be grouped into two categories, diffusion and facilitated diffusion. Both occur without requirement of ATP.

true

What are atoms that vary in the number of neutrons found in their nuclei called?

isotopes

Nuclear membrane, endoplasmic membrane, membrane of Golgi complex and plasma membrane from an end membrane system.

true

The thickness of plasma membrane is proposed to be in the range of 8-24 nm.

true

If sodium has an atomic number of 11 and a mass number of 23, how many neutrons does it have?

12

Why do hydrogen and oxygen form polar covalent bonds within water molecules?

Oxygen is more electronegative than hydrogen, generating a partial negative charge near the oxygen atoms.

Biology is the scientific study of living organisms and their interactions with one another and their environments

true

What is life
Order/organization (Molecules, Cells)
Sensitivity or response to stimuli
Reproduction
Growth and development
Regulation
Homeostasis
Energy processing (metabolism)

All of the above

If the sequence of the 5' to 3' strand is AATGCTAC, then the complementary sequence has the following sequence:

3'-TTACGATG-5'

In which direction does DNA replication take place?

5' to 3'

Which portion of a DAN contains Okazaki fragments?

lagging strand

Which type of point mutation would have no effect on gene expression?

silent

What is the flow of information for the synthesis of proteins according to the central dogma?

DNA to mRNA to protein

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this?

Degeneracy

How many nucleotides are in 12 mRNA codons?

36

The sequence that signals the end of transcription is called the:

stop codon

A poly-A sequence is added at the:

3'-end of a transcript in the nucleus

What are introns?

untranslated DNA sequences in a gene

What process transfers heritable material to the next generation?

replication

Which organelles would be present in high numbers in the leg muscles of a marathon runner?

mitochondria

Choline, ethanol amine, serine and inositol are four organic molecules that are attached to phosphate group in the phospholipids and only serine is negatively charged, others are neutral.

true

Active transport across the membrane means the process needs ATP for transporting molecules across the membrane.

true

Exocytosis is of two types Phagocytosis and Pinocytosis, while Endocytosis is only of one type.

No

Over the last two decades RNA has been found to be of further types; miRNA (micro RNA) and siRNA (small interfering RNA. miRNA are usually 20 nucleotide long and have biological functions. siRNA are again small RNA molecules but they interfere with metabolic processes. Do you think in coming years these RNA will prove to be biologically more involved than we know now.

yes

1. RNA is single stranded, has uracil in place of thymine, contains ribose sugar and not deoxyribose sugar
2. RNA is at least of three types - mRNA, tRNA and rRNA
3. mRNA is transcribed using RNA polymerase
4. tRNA and rRNA and not transcribed.

1, 2, 3 is true

Mitochondria are observed in plant cells that contain chloroplasts. Why do you find mitochondria in photosynthetic tissue?

Mitochondria are required to break down sugars and other materials for energy.

There are multiple nuclei in the eukaryotic cell each separated by its own membrane

False

These are called the garbage disposal units or suicide bags of cells

Lysozomes

Rough endoplasmic reticulum is called so because it has ribosome attached to it.

true

What part of meiosis is most similar to mitosis?

Meiosis II

Describe the sequence of mitotic cell cycle for a pair of chromosome

G2, Mitosis, G1, S

At which of the cell cycle checkpoints do external forces have the greatest influence?

G1

A diploid cell has how many times the number of chromosomes as a haploid cell?

Twice

Which is the longest phase in cell cycle

S phase

How many chromosomes are in G2 phase of human muscle cell

46 pairs but connected at centromere

Cytokinesis differs between plants and animals

plant cells develop a cell plate

The M check point

checks for DNA damage

G2 check point checks for

mainly DNA duplication

Uncontrolled Mitosis leads to humans diseases like

Tumors and Malignant tumors

crossover occurs in

Prophase 1

Non-disjunct chromosomes lead to diseases like

down syndrome

Water moves via osmosis across plasma cell membranes in which direction?

from an area with a high concentration of water to one of lower concentration

1. Transcription
2. Central Dogma
3. Replication
4. Cell organelles
5. Plasma membrane
6. Crossover
7. isotonic

1. DNA to mRNA
2. DNA to mRNA to proteins
3. DNA to DNA
4. Mitochondria
5. Osmosis
6. varying salt
7. no osmosis

Does physical exercise involve anabolic processes, catabolic processes, or both? Give evidence for your answer.

Physical exercise is just a catabolic process. Glucose is broken down into simpler compounds during physical activity and the simpler compounds are then used to provide energy to the muscles for contraction.

Glucose is the sugar most often used in metabolism by the majority of cells on Earth. It is made and used by plants as well as other organisms. Which of the following describes the chemical breakdown of glucose, and what is the name of the chemical process involved in this breakdown?

cellular respiration: C6H1206+602->CO2+6H20+energy

Enzymes facilitate chemical reactions that result in changes to a substrate. How does the induced fit model of enzymes and substrates explain their function?

The enzyme changes shape to fit the substrate causing the transition state to occur

What is removed from pyruvate during its conversion into an acetyl CoA?

carbon dioxide

How many NADH molecules are produced on each turn of the citric acid cycle?

three

1. enzyme that changes the structures
2. Citric Acid Cycle
3. anaerobic
4. Glycolysis
5. NAD+
6. FADH
7. Electron Transport chain

1. isomerase
2. krebs cycle
3. process that does not use oxygen
4. makes pyruvate
5. oxidizing agent
6. reducing agent
7. chemiosmotic ATP generation

Describe the connection between anabolic and catabolic chemical reactions in a metabolic pathway.

Catabolic reactions produce energy and simpler compounds, whereas anabolic reactions involve the use of energy to make more complex compounds.

What does it mean for a system to be in a higher level of entropy? How can it be reduced?

Higher level of entropy refers to higher state of disorder in the system and it can be reduced by input of energy to lower the entropy.

When cellular respiration occurs, what is the primary molecule used to store the energy that is released?

ATP

Which of the following best describes energy?

the ability to do work

Which of the following is the best way to judge the relative activation energies between two given chemical reactions?

Compare the G values between the two reactions.