Bio 101 exam

Order of life

molecule, cell organelle, tissue, organ, organ system, organism, population, community, ecosystem, biosphere

Prokaryote

single cell organism with no nucleus

Eukaryote

single or multi-cell organisms with a nucleus

The classification scheme we looked at in lecture organized life into \____ domains named \______.

three: bacteria, archaea, and eukarya

Sucrose is a disaccharide. It is formed \_____.

When two monosaccharides are connected by dehydration synthesis.

Glycogen

An energy storage polysaccharide found in muscle and liver cells of humans (and other vertebrate animals

Hydrophilic

water loving, forms hydrogen bonds with water

Hydrophobic

water fearing

peptide bond

links amino acids in a polypeptide chain

primary protein structure

the amino acid sequence of a protein, from beginning to end

secondary protein structure

Segments of the polypeptide chain form coiled or folded patterns due to hydrogen bonding within the peptide backbone

tertiary protein structure

overall shape of protein resulting from interactions between R groups

quaternary protein structure

assembly of multiple polypeptides into a functional proteins

How are polymers broken down?

Hydrolysis

How are molecules put together?

dehydration synthesis

hydrolytic enzymes

enzymes that speed up/aid in the breakdown of chemical bonds through the addition of water (hydrolysis)

unsaturated fatty acid

A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail

Fluidity of an animal cell membrane is affected by \____.

degree of saturation and length of phospholipid tails, cholesterol, protein density, and temperature

quorum sensing

The ability of bacteria to sense the presence of other bacteria via secreted chemical signals

Oligosaccharide

A carbohydrate made up of a few (3-10ish) sugars

Starch function

energy storage

cellulose function

provide structure in plants

chitin function

structural support in exoskeleton of insects and fungi cells

chaperones

a type of protein that assists in the folding of other molecules

hydrogen bonds, covalent bonds, ionic bonds, hydrophobic exclusions

interactions between R groups in tertiary structure of proteins

Lipids

fats, phospholipids, steroids

ester linkage

a bond between a hydroxyl group and a carboxyl group

fats are constructed from \______

glycerol and fatty acids

triacylglycerol

three fatty acids linked to one glycerol molecule

Phospolipids

glycerol joined by two fatty acids and a phosphate group

Steroids

lipids characterized by a carbon skeleton consisting of four fused rings

conditions that affect enzyme function

pH and temperature

apo-protein

proteins in lipoprotein complex

lipoprotein complex

* Outer layer consists of single layer of phospholipid molecules
* hydrophilic phosphate heads of the phospholipids face outwards and are in contact with water
* The hydrophobic hydrocarbon tails face inwards and are in contact with the fats
cholesterol molecules are positioned in the phospholipid monolayer - hydrophilic region facing outwards
* Proteins are also embedded in the phospholipid layer (hence the name

low-density lipoprotein (LDL)

delivers cholesterol from liver to cells, bad cholesterol

high-density lipoprotein (HDL)

picks up excess cholesterol from cells, good cholesterol

saturated fats

straight structure, solid at room temperature, high LDL levels, animal fats

unsaturated fats

bent structure, liquid at room temperature, low LDL levels, high HDL levels, plant fats/oils

amphipathic

having both a hydrophilic region and a hydrophobic region

micelle

lipid molecules that arrange themselves in a spherical form in aqueous solutions, hydrophilic heads outside and hydrophobic tails inside

glycolipid

lipid with carb attached

glycoprotein

protein with carb attached

The following are steps of enzyme action. What are the steps in the correct order?


1. enzyme returns to its original tertiary structure and can bind another substrate molecule
2. products are released
3. substrate enters the active site of the enzyme
4. induced fit
5. substrates are converted to products

3, 4, 5, 2, 1

Which is NOT true of denatured enzymes?


1. it no longer has its proper tertiary structure
2. it is biologically inactive
3. it no longer has an active site and cannot bind its substrate
4. it can catalyze its reaction faster than normal
5. chemical bonds and interactions within the protein have been destroyed

4

how is cholesterol carried in our bloodstream?

lipoprotein complexes

If you want to make a membrane that will remain fluid at lower temperatures, you should \___.

increase the number of unsaturated fatty acids in the membrane phospholipids, increase the amount of cholesterol, make more active desaturase enzymes

which of the following would have the most trouble crossing a biological membrane composed only of a phospholipid bilayer?


1. O2
2. CO2
3. Na+
4. H2O
5. A small, hydrophobic molecule

3

How is active transport different than facilitated diffusion?

active transport requires ATP, while facilitated diffusion does not

cells that have rapid water movement would have membranes that are rich in \___.

aquaporins

In its natural environment, water will move into a bacterial cell by diffusion. Is the cytosol of the bacterial cell isotonic, hypertonic, or hypotonic to its environment?

hypertonic

Carrier proteins, channel proteins, and pumps...

are all transmembrane proteins

Bulk transport of substances into a cell is called \_____ and bulk transport of substances out of a cell is called \_____.

endocytosis, exocytosis

An individual is not able to remove LDL from her bloodstream and has extremely high blood cholesterol. Which of the following is a potential explanation for her high cholesterol?


1. she is missing the LDL active transport pump
2. she has deficits in exocytosis
3. she has misfiled LDL receptors
4. she has a deficit in the apolipoproteins in her LDL complexes
5. she has too many LDL receptors in her membranes

3,4

Which of the following can be found in both prokaryotic cells and eukaryotic cells?


1. cytosol
2. nucleoid region
3. organelles
4. plasma membrane
5. nucleus
6. cell wall
7. ribosomes

1,4,6,7

a prokaryotic cell is \____ than a eukaryotic cell

smaller

The outermost boundary of an animal cell is the \___.

plasma membrane

What is a major cause of the size limits for certain types of cells?

the need for a surface area of sufficient area to support the cell's metabolic needs

One way eukaryotic cells compensate for a low surface-to-volume ratio is by \_____.

compartmentalizing their activities into organelles

Two types of nucleic acids, DNA and RNA, enable living organisms to produce their complex components from one generation to the next.

Select all choices that correctly describe DNA.


1. deoxyribonucleic acid
2. contains the nucleotides adenine (A), guanine (G), cytosine (C), uracil (U)
3. its nucleotides contain the sugar ribose
4. found in nucleus and not in cytosol
5. found in nucleus and cytosol
6. copy of instructions in DNA; is used to make proteins that run the cell
7. genetic material organisms inherit from their parents; contains all of the instructions that program cell activities
8. its nucleotides contain the sugar deoxyribose
9. ribonucleic acid
10. usually exists and functions as a single polynucleotide strands
11. contains the nucleotides adenine (A), guanine (G), cytosine (C), thymine (T)
12. consists of two polynucleotides that spiral around each other to form a double helix

1,4,7,8,11,12

The three dimensional structure of DNA is described as a double helix. The two polynucleotide strands of the double helix are connected to each other by ________, while the nucleotides within a single polynucleotide stand are connected by ______ .

hydrogen bonds between complementary nitrogenous bases; phosphodiester bonds

A single polynucleotide strand has a 5' and a 3' end. 5' and 3' refer to \___.

the numbers assigned to the carbons of the pentose sugar

In a double helix, the two strands are oriented in opposite directions with respect to their 5' and 3' ends. In other words, the two strands run \_____ to each other.

antiparallel

Which of the following statements about bulk transport is ACCURATE?


1. vesicles are involved in endocytosis and exocytosis
2. large molecules can be released from cells by endocytosis
3. pinocytosis brings in much larger compunds than phagocytosis
4. receptor-mediated endocytosis is less selective than phagocytosis and pinocytosis

1

Penicillin is a broad-spectrum antibiotic that interferes with the synthesis of peptidoglycan cell walls. You take penicillin to treat strep throat. Penicillin kills bacterial cells and not yours because \______.

your cells do not have a cell wall

Fecal transplants have been effective in treating patients with recurrent Clostridium difficile infections. How do fecal transplants work?

the healthy microbiome from the donor outcompetes the C. difficile that has colonized the patient's gut

Chloroplast

converts light energy into chemical energy in a photosynthetic organism

Golgi apparatus

in the endomembrane system, a warehouse for receiving, sorting, and shipping proteins made in the rough ER

lysosome

contains functional hydrolytic enzymes

Microfilaments

intertwined strands of actin subunits that underlie cell structure

Microtubules

hollow tubes made of tubular subunits that are important in vesicle transport in the endomembrane system

Mitochondrion

primary site of ATP synthesis

nucleus

contains most of the cells DNA

Peroxisome

organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product, then converts it to water

ribosome

Synthesizes proteins, subunits of this structure are made in the nucleolus

Rough Endoplasmic Reticulum

proteins that will be secreted from the cell are made in this compartment

Smooth Endoplasmic Reticulum

synthesis of oils, phospholipids, and steroids

You decide you want to study the function of the nuclear lamina. Based on what you learned in lecture and pre-lecture videos, which of the following would be the LEAST likely to be a useful model organism?

A. Drosophila melanogaster (fruit fly) \n B. Escherichia coli (a bacterium) \n C. Arabidopsis thaliana (plant) \n D. Dictyostelium discoideum (a protist) \n E. Saccharomyces cerevisiae (yeast, a fungus) \n F. Danio rerio (zebrafish)

B

You make a knock out mouse that does not make lamin proteins. Assuming the mouse survives, which of the following would you likely observe?


1. normal nuclei
2. disorganized chromatin (DNA)
3. defective ribosomes
4. abnormally-shaped nuclei
5. inability to move vesicles from the ER to the Golgi
6. abnormal cell wall structure

2,4

The nuclear envelope...


1. it encloses the nucleus, separating it from the cytoplasm
2. it contains pores
3. the nuclear side (non-cytosolic side) of the envelope is lined with a nuclear lamina
4. it is a membrane consisting of one phospholipid bilayer
5. it is the site of ribosome production

1,2,3

You genetically engineer a line of fruit flies to produce DNA polymerase with no nuclear localization signal (NLS). Which of the following is the likely result?


1. the lamin proteins will go into the nucleus but will not fold normally
2. the DNA polymerase will not go into the nucleus, but the fruit flies and their nuclear function will be normal
3. the DNA polymerase will go through the endomembrane system and be released from the cell by exocytosis
4. nothing, DNA polymerase is made in the nucleus
5. the cells of the fruit fly will not replicate their DNA

5

Which of the following supports the theory that mitochondria and chloroplasts evolved from prokaryotic cells?

Mitochondria and chloroplasts _______.


1. have cell walls made of cellulose
2. are similar in size to typical prokaryotic cells
3. have circular chromosomes
4. divide by binary fission
5. have ribosomes that structurally resemble prokaryotic ribosomes

2,3,4,5

Replication of eukaryotic chromosome begins

at specific sites called origins of replication

The initial nucleotide chain that is produced in DNA synthesis is a short stretch of \______ called a \_______ that is synthesized by the enzyme \_______.

RNA; primer; primase

You develop a technology to visualize a growing DNA strand. To which end are new nucleotides being added to the growing strand?

3'

DNA ligase

connects DNA fragments by joining sugar-phosphate backbones

DNA polymerase I

removes the RNA primer and replaces it with DNA

DNA polymerase III

Adds new DNA nucleotides to a replicating DNA molecule

Helicase

An enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands.

single strand binding proteins

bind to the unpaired DNA strands, keeping them from re-pairing

Topoisomerase

relieves the strain caused by tight twisting ahead of the replication fork by breaking, swiveling, and rejoining DNA strands

passive transport

movement of cells down a concentration gradient, no energy needed

active transport

movement of cells against a concentration gradient, energy needed

types of passive transport

simple diffusion, facilitated diffusion, osmosis

vesicular transport (bulk)

movement into and out of cell by vesicles

Vesicle

membrane bound sac

Exocytosis

Process by which a cell releases large amounts of material

Endocytosis

process by which a cell takes material into the cell

Phagocytosis

Cell eating, big molecules or entire cell go into cell to be broken down

Pinocytosis

Cell drinking, cell membrane brings in whatever happens to be outside of cell, uses what it wants, gets rid of what it doesn’t

Receptor- mediated endocytosis

very selective, brings in 1 specific molecule using receptors