Exam 1 Cell Biology Dr. Reeves KSU

The function of many proteins is regulated by covalent modifications. Many such protein modifications and their effects are readily reversible. The effect of which of these covalent modifications on its target protein is NOT rapidly reversible? A) phosphorylation B) palmitoylation C) polyubiquitination D) acetylation

C) polyubiquitination

Non-covalent interactions are much weaker than covalent bonds, but they're critical for the stable folding of proteins. Why? A. All amino acid side chains are capable of forming hydrogen bonds. B. Electrostatic interactions are very strong in aqueous interactions. C. Although weak individually, the combination of many weak non-covalent bonds together can create strong, stable interactions. D. Once formed, non-covalent bonds can only be broken by enzyme catalyzed hydrolysis.

C. Although weak individually, the combination of many weak non-covalent bonds together can create strong, stable interactions.

If protein folding is determined by the sequence of amino acids in the polypeptide chain, why are chaperone proteins needed to assist folding in the cell?A. Some proteins cannot fold on their own. B. Protein folding is energetically unfavorable. C. Certain proteins easily aggregate with other proteins. D. Proteins constantly unfold and refold.

C. Certain proteins easily aggregate with other proteins. All proteins can fold on their own without assistance due to the energetically favorable interactions between amino acid side chains and/or the polypeptide backbone. However, the cytoplasm is crowded and some proteins can form favorable interactions with other proteins before they have a chance to fold. These aggregates could impede proper folding.

Some drugs, such as anti-cancer drug Gleevec, are competitive inhibitors of enzymes. Gleevec specifically targets a kinase that is activated in certain types of cancer. Given what we learned about competitive inhibitors, how does Gleevec function? A. Gleevec directly blocks transcription of the kinase B. Gleevec binds to a regulatory site on the kinase and inhibits its activity. C. Gleevec binds to the active site of the kinase and interferes with substrate binding. D. Gleevec binds to the active site of the kinase and reduces the enzyme's Vmax.

C. Gleevec binds to the active site of the kinase and interferes with substrate binding.

The function of many proteins is regulated by covalent modifications. Many such protein modifications and their effects are readily reversible. The effect of which of these covalent modifications on its target protein not rapidly reversible? A. Acetylation B. Phosphorylation C. Poly-ubiquitination D. Palmitoylation

C. Poly-ubiquitination Leads to degratdation

Enzymes can have both active and regulatory sites. What is the purpose of these sites? A. The binding of CTP at a regulatory site on the protein causes increased production of carbamoyl aspartate. B. The binding of CTP at the active site on the protein causes increased production of carbamoyl aspartate. C. The binding of CTP at a regulatory site on the protein causes decreased production of carbamoyl aspartate. D. The binding of CTP at the active site on the protein causes decreased production of carbamoyl aspartate.

C. The binding of CTP at a regulatory site on the protein causes decreased production of carbamoyl aspartate. The binding of CTP at a regulatory site on the protein causes decreased production of carbamoyl aspartate. One of the final products of the pathway that this enzyme is involved in, cytosine triphosphate (CTP), binds to the enzyme to turn it off whenever CTP is plentiful. This is known as feedback inhibition and this enzyme is a very common example of the allosteric regulation of an enzyme.

Why do phospholipids aggregate to form cell membranes? Choose one: A. They are acids. B. They are attached to sugars. C. They are amphipathic. D. They are water-loving. E. They are water-fearing.

C. They are amphipathic.

Ras is a GTP-binding protein involved in cell proliferation (division). In its active form, with GTP bound, Ras activates cell signaling pathways that promote cell division. Mutations in the gene that encodes Ras can lead to cancer. How might mutations in the gene encoding Ras lead to the uncontrolled proliferation characteristic of cancer cells? A. They increase the protein's affinity for GDP. B. They decrease the protein's affinity for GTP. C. They decrease the rate at which Ras hydrolyzes GTP. D. They increase the rate at which Ras hydrolyzes GTP. E. They prevent Ras from being made.

C. They decrease the rate at which Ras hydrolyzes GTP. A mutation that decreases the rate at which Ras hydrolyzes GTP would be a logical mutation in the gene encoding Ras that could lead to the uncontrolled proliferation characteristic of cancer cells. Ras is a G protein that is activated upon GTP binding. If a mutation happened that caused a decrease in the ability of Ras to hydrolyze that GTP, then cell-proliferative Ras signaling would lead to cancer.

Plasmin and cathepsin G are both serine proteases. Which of these statements about these proteins is false? A. They are homologs B. They are members of the same protein family C. They have identical sequences and functions D. Their three dimensional structures are similar to that of chymotrypsin.

C. They have identical sequences and functions

Which type of lipid is not a component of cell membranes? A. Cholesterol B. Glycolipids C. Triacylglycerol D. Phospholipids

C. Triacylglycerol

Which of the following is UNLIKELY to be hydrophilic? Choose one: A. a molecule with a lot of polar covalent bonds B. a salt that is held together with ionic bonds C. a molecule with primarily nonpolar covalent bonds D. a molecule that forms hydrogen bonds with water

C. a molecule with primarily nonpolar covalent bonds

Which model organism: transparent = live imaging of cell behavior cell differentiation and development apoptosis (controlled cell death)

C. elegans (nematode worm)

Genetic changes followed by selection are best described as the fundamentals of what process? A. regeneration B. reproduction C. evolution D. genetic drift E. DNA replication

C. evolution

Which of the following microscopy techniques allows the observation of living cells (i.e., NOT fixed cells)? A. transmission electron microscopy B. There are no microscopy techniques suitable for the observation of living cells. C. fluorescence microscopy D. scanning electron microscopy

C. fluorescence microscopy Light microscopy, which also includes fluorescence microscopy, can be used to view living cells. Electron microscopy requires cell fixation and extensive preparation of the samples, which kills the cells.

Which term describes genes (and gene products) related by a common ancestral gene? A. familial B. vestigial C. homologous D. analogous E. superfluous

C. homologous

What is the covalent linkage between two adjacent amino acids in a protein called? Choose one: A. phosphodiester bond B. glycosidic bond C. peptide bond D. hydrogen bond E. phosphoanhydride bond

C. peptide bond

What is a methyl group? Is it nonpolar, reactive, or phosphate?

CH₃ Nonpolar

What is a carboxyl group? Is it nonpolar, reactive, or phosphate?

COOH Reactive group

allows finer gene editing, can remove gene OR replace wildtype gene with mutant works in almost all model organisms. Recently invented technique.

CRISPR

What can happen when DNA mutations result in altered side chains?

Can alter function if new side chains have different chemical properties

Oxidize ("burn") food to produce ATP. It's highly efficient. It consumes oxygen and releases CO2.

Cellular respiration

What are the four parts of an amino acid?

Central α-carbon Amino group Carboxyl (COOH) group Side chain

_______ increase efficiency and reliability, but the sequence still determines what correct conformation should be.

Chaperones

According to _______ and his theory of evolution from 1859, random variation and natural selection have created the enormous diversity of life today.

Charles Darwin

When amino acids mutate, the effect of the mutation depends on what three things?

Chemical properties Size of side chain Where the mutation occurs in the protein

An essential component in cell membranes. Also used to create steroids.

Cholesterol

small organic molecules that help catalyze reactions. Biotin (vitamin B7) : many enzymes that transfer carboxyl groups

Coenzymes

_______ are found in keratin and myosin motor proteins.

Coiled coils

________ inhibitors directly interfere with substrate binding

Competitive

What type of microscopy method optically sections specimen into fine 3-dimensional detail. Reconstruction is possible and cells can be living or fixed.

Confocal microscopy (type of fluorescent light microscopy)

What are the two types of light microscopes?

Conventional Light Microscope Fluorescent Microscopes

______ bonds have specific geometries.

Covalent

Examining cell structure

Cytology and microscopy

What are the three main methods that scientists use to study cell biology?

Cytology and miscroscopy Biochemistry Genetics

The study of cell structure.

Cytology/microscopy

Modern cell biology is the convergence of what three fields of science.

Cytology/microscopy Biochemistry Genetics

Everything inside plasma membrane, except nucleus. Membrane bound organelles, cytoskeleton, and cytosol

Cytoplasm

Important for controlling cell shape, cell strength and cell movement.

Cytoskeleton

Required for intracellular transport and organization and also cell division.

Cytoskeleton

System of protein filaments criss-crossing cytoplasm.

Cytoskeleton

Densely packed proteins, ions, other molecules. Constantly moving

Cytosol

Sugar monomers and the polymers built from them have many important functions for cells. Which of these is not a function of sugars? A) They can be a component of nucleotides. B) They can be attached as modifications to proteins and lipids. C) They can be a structural component of cell walls. D) All four of these are functions of sugars and/or sugar polymers. E) They can be used to store energy.

D) All four of these are functions of sugars and/or sugar polymers.

Which of the following is true for homologous genes? A) All of these statements are characteristics of homologous genes. B) Homologous genes always have identical functions. C) Homologous genes always have identical sequences. D) Homologous genes always share an evolutionary origin.

D) Homologous genes always share an evolutionary origin.

In this organelle, molecules are digested for either export or re-use. A) Endoplasmic Reticulum B) Endosomes C) Golgi apparatus D) Lysosomes

D) Lysosomes

Which of the following statements comparing a human liver cell to a human neuron is TRUE? A) The two types of cells encode identical genes in their genomes, and express identical sets of proteins. B) The two types of cells encode different genes in their genomes, but express identical sets of proteins. C) The two types of cells encode different genes in their genomes and don't express identical sets of proteins. D) The two types of cells encode identical genes in their genomes, but don't express identical sets of proteins

D) The two types of cells encode identical genes in their genomes, but don't express identical sets of proteins

Which of these is not a fundamental feature shared by all cells? A) They are capable of producing and storing usable energy B) They are surrounded by a lipid bilayer membrane. C) They are capable of reproducing themselves D) They encode their genetic information in DNA inside a nucleus.

D) They encode their genetic information in DNA inside a nucleus.

GTP binding proteins are considered molecular switches, which can be toggled between an active and an inactive state. If you wanted to decrease the activity of your favorite GTP binding protein, you could introduce a mutation that A) decreases the rate at which the protein hydrolyzes GTP. B) increases the rate at which the enzyme releases GDP. C) increases the rate at which the protein binds to GTP. D) decreases the rate at which the protein releases GDP.

D) decreases the rate at which the protein releases GDP.

You are interested in studying the movement of organelles within living eukaryotic cells as they undergo cell division. Which of these microscopy techniques would NOT be a good choice. A) light microscopy B) fluorescent microscopy C) confocal microscopy D) electron microscopy

D) electron microscopy

Which of these atoms can form a maximum of 3 covalent bonds? A) oxygen B) carbon C) hydrogen D) nitrogen

D) nitrogen

Nucleotides can form long polymers called nucleic acids. Which of these statements about nucleic acids is false? A. Nucleic acids have a polarity, with a 5' end and a 3' end. B. The phosphodiester bonds between nucleotides are broken by hydrolysis reactions. C. Nucleic acids are formed from nucleotides by condensation reaction. D. Cell contain only one type of nucleic acid: DNA.

D. Cell contain only one type of nucleic acid: DNA.

Which of these statements about protein phosphorylation is FALSE? A. Phosphorylation adds a highly charged group and can alter the phosphorylated protein's 3D conformation. B. Addition of a phosphate group to a protein can create new binding sites on the protein. C. Some proteins are activated by phosphorylation while others are inactivated by it. D. Phosphorylation is reversible because phosphatases add phosphate groups to proteins and kinases remove them.

D. Phosphorylation is reversible because phosphatases add phosphate groups to proteins and kinases remove them. Kinases add and phosphatases remove

Regarding acids, bases, and pH, which of these statements is true?Choose one: A. Substances that release protons when they dissolve in water are termed bases and result in a pH higher than 7. B. Substances that release protons when they dissolve in water are termed acids and result in a pH higher than 7. C. Substances that release protons when they dissolve in water are termed bases and result in a pH lower than 7. D. Substances that release protons when they dissolve in water are termed acids and result in a pH lower than 7.

D. Substances that release protons when they dissolve in water are termed acids and result in a pH lower than 7.

Scientists were studying yeast cells in which a mutation inactivated a gene required for cell division. Without this gene—and the protein it encoded—these mutant yeast cells were unable to divide normally. But the scientists discovered that introducing a related protein from human cells could "rescue" these mutant yeast cells, allowing the cells to resume normal division. Based on this finding, what is the most likely conclusion you could make? A. Modern humans most likely obtained their cell-division proteins from ancient yeast. B. Yeast cells most likely obtained their cell-division proteins from the cells of early humans. C. Yeast and humans diverged from a common ancestor much more recently than previously thought, perhaps fewer than a million years ago. D. The proteins that control cell division in yeast and humans are functionally equivalent and have been conserved, almost unchanged, for more than a billion years. E. Yeast cells require human proteins to divide.

D. The proteins that control cell division in yeast and humans are functionally equivalent and have been conserved, almost unchanged, for more than a billion years.

Lipids can include all except which of the following? Choose one: A. oils B. fatty acids C. triacylglycerol D. amino acids E. steroids

D. amino acids

How are covalent bonds in the cell rapidly broken? Choose one: A. by the large electrical force across membranes B. by energetic molecular collisions with potassium ions C. by energetic molecular collisions with water molecules D. by enzyme catalysis that is specific between protein and substrate

D. by enzyme catalysis that is specific between protein and substrate

Disulfide bonds stabilize protein shape outside the cell by A. hydrogen bonds with water molecules. B. noncovalent bonds between charged side chains. C. hydrophobic interactions within the lipid bilayer. D. covalent bonds between cysteines.

D. covalent bonds between cysteines.

What are protein families? A. proteins that are produced at the same time on the ribosome that, once produced, regulate the activity of each other B. sets of proteins with the same functions that are commonly found only in organisms of the same species C. proteins found specifically in one type of cell line that tend to interact with each other D. evolutionarily related proteins that are similar in amino acid sequence and three-dimensional conformation

D. evolutionarily related proteins that are similar in amino acid sequence and three-dimensional conformation

Which carbohydrates contain hundreds or thousands of sugar subunits? Choose one: A. oligosaccharides B. monosaccharides C. disaccharides D. polysaccharides

D. polysaccharides

What reaction involving ATP releases a large amount of energy? Choose one: A. the release of the hydroxyl group B. the release of adenine C. the release of the base D. the release of the terminal phosphate group E. the release of the sugar group

D. the release of the terminal phosphate group

Primary structure sequence is encoded in the cell's _____.

DNA

The genetic information of the cell organized into 1 or more chromosomes

DNA

What is more stable and used for long term storage, DNA or RNA?

DNA

There are a vast number of possible protein sequences; only a small fraction are functional, stable proteins. That means that functional domains and proteins are conserved. An example of this conservation are the ________ of _____.

DNA binding domains of transcription factors

E coli is a model for other bacteria. Also used to study deeply conserved processes such as ______ and the _____. Eukaryotic specific traits cannot be studied

DNA replication and the genetic code

One _____ ≈ one hydrogen atom.

Dalton

List the three polymers of monosaccharides in order of smallest to largest.

Disaccharides Oligosaccharides Polysaccharides

Covalent linkages between Cysteine side chains. Stabilizes extracellular protein. Bond catalyzed in ER.

Disulfide bonds

independently folding regions within a polypeptide. They often have distinct functions

Domains

_____ and _____ bonds limit rotation and influence possible 3D conformations.

Double and triple

Which model organism: Regulation of body plan development Chromosome organization/structure

Drosophila (fruit flies)

Model for other bacteria. Also used to study deeply conserved processes such as DNA replication, the genetic code. Eukaryotic specific traits cannot be studied

E coli

Although interested in understanding how cancer develops in humans, Dr. Hartwell chose to use the single-celled yeast S. cerevisiae for his research. As we discussed in our group meetings, which of the following are reasons that S. cerevisiae was a good choice of model organism for studying cancer development? 1) S. cerevisiae cells divide quickly and are relatively easy to manipulate genetically. 2) As fellow eukaryotes, yeast and human cells use similar extracellular signaling methods to control tissue and organ development. 3) As fellow eukaryotes, it is reasonable to assume that yeast and human cells might control their cell cycle in similar ways. A) 1 and 2 B) 1, 2 and 3 C) 2 and 3 D) only 1 E) 1 and 3

E) 1 and 3

You are interested in studying the endosymbiotic relationship between mitochondria and eukaryotic cells. Which of these model systems would be least appropriate? A) M. musculus (mice) B) Arabidopsis (flowering plant) C) Drosophila (fruit flies) D) S. cerevisiae (yeast) E) E. coli (bacteria)

E) E. coli (bacteria)

Which statement represents the cell theory? A. All cells resemble square or rectangular chambers. B. All cells can be seen using a microscope. C. All cells contain DNA. D. All cells require a continual input of energy to sustain life. E. All cells are formed by the growth and division of existing cells.

E. All cells are formed by the growth and division of existing cells.

Which of these is not a function of sugars and/or sugar polymers? A. Can be attached to proteins or lipids B. Used for energy storage C. Is a component of nucleotides D. Can be a structural component of cell walls E. All of these are functions

E. All of these are functions

Which of the following correctly describes phosphorylation of a protein? A. It is an irreversible protein modification. B. It is catalyzed by a protein phosphatase. C. It always increases the protein's activity. D. It always decreases the protein's activity. E. It can increase or decrease the protein's activity.

E. It can increase or decrease the protein's activity. The phosphorylation of a protein can either increase or decrease the protein's activity, depending on the site of phosphorylation and the structure of the protein. Binding sites can either be exposed to or hidden by these conformational changes.

Which model system would be the best choice for scientists studying how human lungs develop? A. Human neural cell tissue culture B. S. cerevisiae (yeast) C. E. coli (bacteria) D. Dosophila (fruit fly) E. M. musculus (mice)

E. M. musculus (mice)

In what way are all cells alike? A. They require other cells to survive and reproduce. B. They are round in shape. C. They are about one-tenth of a millimeter in diameter. D. They are surrounded by a tough outer coat made of protein. E. They store their genetic instructions in DNA.

E. They store their genetic instructions in DNA.

For a given protein, hydrogen bonds can form between which of the following? A. atoms in the polypeptide backbone B. atoms of two peptide bonds C. atoms in two side chains D. a side chain and water E. all of the above F. none of the above

E. all of the above

Which part of an amino acid gives it its unique properties? A. peptide bond B. amino group C. carboxyl group D. α-carbon E. side chain

E. side chain

What does the primary structure of a protein refer to? A. the overall three-dimensional shape of the protein B. the structure that forms first as the protein folds into its most stable form C. the locations of the protein's α helices and β sheets D. the locations of the peptide bonds that form the protein's backbone E. the linear amino acid sequence of the protein

E. the linear amino acid sequence of the protein

Which structure or process mediates the exchange of materials between the endoplasmic reticulum, Golgi apparatus, the lysosomes, and the outside of the cell? A. extracellular matrix B. simple diffusion C. peroxisomes D. cytosol E. transport vesicles

E. transport vesicles

Disulfide bonds are covalent linkages between Cysteine side chains. Stabilizes extracellular protein. Bond catalyzed in __(organelle)___.

ER

Tendency of atom to attract electrons.

Electronegativity

Site of protein and lipid synthesis.

Endoplasmic reticulum

What are the three main functions of small organic molecules (fatty acids, sugars, amino acids, and nucleotides)?

Energy source during catabolism (food breakdown) Signaling molecules Building blocks for large molecules

Essential catalysts of the cell. Accelerate specific chemical reactions by lowering activation energy. Are not changed themselves

Enzymes

What type of protein: Catalyze covalent bond breakage and formation

Enzymes

The third domain of life. Includes animals, plants, fungi and protists (algae, protozoa, amoeba, diatoms, etc). Can be single celled organisms or multicellular organisms of varying complexity

Eukaryotes

E coli is a model for other bacteria. Also used to study deeply conserved processes such as DNA replication, the genetic code. _______ specific traits cannot be studied

Eukaryotic

True or False: All genes are expressed in a cell at all times.

False

True or False: There are a total of 20 known amino acids on earth.

False. There are 20 used in protein synthesis

True or False: Mitochondria all have the "peanut" shape.

False. They can vary in shape, size, and number.

True or False: A lysozyme catalyzes a reaction by one method.

False. It uses many (3) techniques. Strains substrate into transition state, alters electron distribution, forms covalent bond with substrate.

True or False: Eubacteria and archaea are more closely related than they are to eukaryotes because they both lack nuclei.

False. While they both lack nuclei, they are as genetically different as they are to eukaryotes.

What are the four main small organic molecules?

Fatty acids Sugars Amino acids Nucleotides

The GTP binding proteins are "on" when they're bound to [GDP/GTP] and "off" when they're bound to [GDP/GTP].

GTP; GDP

GTP binding proteins are also called...

GTPases

A method of studying cell biology that asks the question, "how do changes in genes (and their products) affect cell behavior and function?"

Genetics

The study of inheritance of structure and function of cells.

Genetics

Modern anti-cancer treatment. Inhibits a kinase that promotes cell division

Gleevec

There is a wide variety of shapes of proteins. However, some regular patterns are seen. What are two of these common shapes?

Globular proteins Fibrous proteins

The dominant energy source in cells.

Glucose

______ and _______ are two examples of fatty acid derivatives.

Glycolipid and phospholipid

Covalent bonds between hydroxyl groups formed by condensation reactions. This reaction is energetically unfavorable.

Glycosidic bonds

In this organelle, molecules are processed and modified then sorted for continued transport.

Golgi

Next stop after the ER for proteins and lipids.

Golgi apparatus

The main molecules that are exported by exocytosis are extracellular proteins/lipids that were sorted in ______.

Golgi apparatus

Side chains alternate _____ and _____ the β sheet

above and below

Non-covalent bonds are weak but they can gain strength if they...

act together

Protein phosphorylation [adds/takes away] a highly charged phosphoryl group to proteins. Causes a conformational change that alters function. Reversible.

adds

The specimen on conventional light microscopes is [alive/dead].

alive. Can also be fixed and sectioned.

Ribosomes are found in all domains of life. This illustrates that...

all cells are related (homology)

Feedback regulation often involves _______ regulation

allosteric

Mitochondria are in [almost all/very few] eukaryotes.

almost all

Protein sequence always read from ______ terminus to ______ terminus. This is the same direction as ribosome adds new amino acids.

amino terminus (N term.) to carboxyl terminus (C term)

Fatty acids are [hydrophilic/hydrophobic/amphipathic].

amphipathic

Glycolipids and phospholipids are both highly _____.

amphipathic

Cells vary greatly in _______ and ______.

appearance and structure

Covalent bonds are very strong in ______ environments.

aqeuous

Steroids are hydrophobic molecules based around 4 ________. Type of lipid.

aromatic rings

Biochemical ______ can tell you what the protein does and how.

assays

oxygen carrying proteins in red blood cells; require Fe4+ containing heme groups

Hemoglobin

break opens cells without destroying contents

Homogenize

_______ genes can have similar functions

Homologous

_________ traits share an evolutionary history.

Homologous

Any genes related by shared inheritance

Homologs

Genes/structures/etc that have close similarity due to shared evolutionary origins.

Homology

_______ determines fatty acid identity. They vary in length and may contain single and double bounds.

Hydrocarbon tail

Non-covalent bonds stabilize protein folding. ______ bonds are very common because amino acids have many polar groups.

Hydrogen

_____ bonds determine if organic molecules mix well in water.

Hydrogen

What type of enzyme: General term for enzymes that catalyze a hydrolytic cleavage reaction.

Hydrolase

Hydro[philic/phobic] peptide backbone buried inside alpha helix.

Hydrophilic

What are the two parts of fatty acids?

Hydrophilic carboxyl group head Hydrophobic hydrocarbon tail

These are the two parts of fatty acids: Hydro[philic/phobic] carboxyl group head Hydro[philic/phobic] hydrocarbon tail

Hydrophilic head Hydrophobic tail

The actual site of cellular respiration in a mitochondria.

In the folds of the inner membrane

What's the advantage of electron microscopes when compared to light microscopes? What are two limitations?

Increased resolution, but it cannot image living specimens and specimen require special treatment.

Which type of cytoskeleton: Used for mechanical strength and stress resistance of animal cells

Intermediate filaments

[Vertebrates/Invertebrates] are multicellular animals with easily manipulated genomes.

Invertebrates

What type of enzyme: Catalyzes the rearrangement of bonds within a single molecule.

Isomerase

One of the reasons why people believe mitochondria and chloroplasts are derived from engulfed bacteria is that they have their own genomes and ribosomes. What does their DNA do?

It encodes many (not all) of their proteins.

One of the requirements of a living organism is that is must be distinct and independent from its surroundings. What makes it "distinct" and what makes it "independent?"

It has a highly organized interior to be distinct. It is capable of homeostasis to be independent.

What type of enzyme: Catalyzes the addition of phosphate groups to molecules. The protein version of these are an important group that attach phosphate groups to proteins.

Kinase

substrate concentration that yields half Vmax. A smaller one = stronger binding

Km

When there is a low substrate concentration, the rate depends on ____. When there is a high substrate concentration, the rate depends on ____.

Km; Vmax

Main organic component of cell by mass

Large molecules

Hydrocarbon tail determines fatty acid identity. The identity is based on ______ and ______.

Length and saturation (types of bonds, single or double)

the specific molecule bound by a particular protein. Each binding site binds only 1 (or a few) possible of these.

Ligands

What type of enzyme: Joins two molecules together. The DNA version joins two DNA strands together end to end.

Ligase

What are the two major classifications of microscopes?

Light and electron

You need to see living organelles. What type of microscope (light or electron) do you choose?

Light. These microscopes can see organelles, while electron microscopes can't see living organisms.

Water insoluble (hydrophobic) molecule that is soluble in organic solvents

Lipid

What type of covalent modification: addition of fatty acids can anchor protein in membrane

Lipids

_______ proved that cells cannot arise spontaneously.

Louis Pasteur

The garbage disposal of the cell.

Lysosome

In endocytosis, transport vesicles buds off plasma membrane. Endosomes is used as a sorting station. _____ is used for digestion of waste and endocytosed molecules.

Lysosomes

secreted hydrolase. Severs polysaccharide chains of bacterial cell walls in a hydrolysis reaction.

Lysozyme

Large molecules that are polymers of small monomers

Macromolecules

In 1838, ________ found that all plant tissues are made of cells.

Matthias Schleiden

What are the three things inside the cytoplasm?

Membrane bound organelles Cytoskeleton Cytosol

Sequences of enzyme catalyzed reactions

Metabolic pathways

What small molecule that helps enzymes: Carboxypeptidases remove the last amino acid of polypeptide chains. Requires a tightly bound zinc ion

Metal ions

What type of covalent modification: alters chemical properties of side chain

Methylation and Acetylation

Which model organism: most genes have human homologues knockout version of this species exist for nearly all non-essential genes

Mice

Scientists can develop and share tools and resources for a given species (model organisms). One example of this is knockout mice. What is this?

Mice with certain genes that are not present. Rather than breeding yourself, you can order these mice and conduct experiments. If everyone used their own model organism, there probably wouldn't be enough of a need for knockout mice.

The highways that move transport vesicles in the cell.

Microtubule

Which type of cytoskeleton: Used for intracellular transport, chromosome segregation during mitosis

Microtubule

_______ and ________ are most likely derived from engulfed bacteria.

Mitochondria and chloroplasts

Why do we think mitochondria came first?

Mitochondria are present in all eukaryotes and all are genetically similar. Chloroplasts are only present in plants/algae.

Which organelle was most likely acquired first, mitochondria or cholorplasts?

Mitochondria were first

Species used in research as a representative for a larger group.

Model organism

_____-ubiquitination can alter function

Mono

What type of protein: Generate movement in cells and tissues.

Motor proteins

_______ can shift their conformation to "walk" along the cytoskeleton.

Motor proteins

_______ drive muscle contraction, cell movement, intracellular trafficking and cell division!

Motor proteins

Proteins have a polarity. They are synthesized from ___-terminus to ___-terminus

N terminus to C terminus

What is an amino group? Is it nonpolar, reactive, or phosphate?

NH₂ Reactive

What is C. elegans?

Nematode worm

_____ affect an atom's stability but not its chemical properties.

Neutrons

What is a competitive inhibitor's effect on Vmax?

No effect. Vmax remains unchanged.

Polar or Nonpolar bond: C-H

Nonpolar

What are the three important chemical groups in organic chemistry?

Nonpolar groups Reactive groups Phosphate group

What type of enzyme: Breaks down nucleic acids by hydrolyzing bonds between nucleotides.

Nuclease

Sometimes abbreviated as NTPs and dNTPs.

Nucleotides

_______ are also a source of -OPO₃²⁻ groups for phosphorylation reactions.

Nucleotides

What is the relationship between nucleic acids and nucleotides?

Nucleotides form nucleic acids

Hydrogen bonds occur when hydrogen is bonded by ____ or ____.

O or N

What is a hydroxyl group? Is it nonpolar, reactive, or phosphate?

OH Reactive group

What type of enzyme: General name for enzymes that catalyze reactions in which one molecule is oxidized while the other is reduced. Enzymes of this type are often called oxidases, reductases, or dehydrogenases.

Oxido-reductase

What is a phosphate group?

PO₄²⁻

Organelle responsible for the inactivation of toxic molecules by H₂O₂.

Peroxisomes

A ______ will remove a phosphate from a protein and add it to ADP.

Phosphatase

What type of enzyme: Catalyzes the hydrolytic removal of a phosphate group from a molecule.

Phosphatase

Bonds formed by condensation reaction between 5' phosphate and 3' hydroxyl.

Phosphodiester bonds

The harvesting of light energy to produce sugar molecules (energy source). It releases oxygen.

Photosynthesis

Polar or Nonpolar bond: C=O

Polar

Polar or Nonpolar bond: N-H

Polar

Polar or Nonpolar bond: O-H

Polar

[Polar/Nonpolar] bonds allow molecules to interact via hydrogen bonds.

Polar

_____ is established during production of growing polymer.

Polarity

_____-ubiquitination targets proteins for degradation by the proteasome

Poly

What type of enzyme: Catalyzes polymerization reactions such as the synthesis of DNA and RNA.

Polymerase

______ are polymers of amino acids

Polypeptides

Amino acid sequence (encoded in the protein's gene).

Primary structure

Identify key differences between prokaryotes (the domains of eubacteria and archaea) and eukaryotes and consider the impact these different characteristics will have on cell behavior.

Prokaryotes lack a nucleus. This means their DNA is in the cytoplasm where transcription and translation occurs. Eukaryotes have a nucleus that stores DNA.

What type of enzyme: Breaks down proteins by hydrolyzing peptide bonds between amino acids.

Protease

Adds a highly charged phosphoryl group to proteins. Causes a conformational change that alters function. Reversible.

Protein phosphorylation

Covalent modifications can directly regulate the activity of protein. What is one example of this?

Protein phosphorylation

The most common macromolecule in cells.

Proteins

proteins with multiple polypeptides

Quaternary structure

You can remove a protein entirely with _______.

RNA interference

Sequences and quantitates all mRNAs expressed in a sample

RNAseq

What type of protein: Detect signals and transmit them to the cell's response machinery.

Receptor protein

The ______ is important for membrane transport and energy production.

Relative

______ covalently binds to rhodopsin protein. It can absorb light and change shape (synthesized from vitamin A).

Retinal

light receptor protein in rod cells of eye

Rhodopsin

_______ built own microscope in 1665 observed small compartments in cork named them "cells" after the rooms in monasteries.

Robert Hooke

______ added a third critical point to Schwann's cell theory.

Rudolf Virchow

This model organism has all the advantages of fast-growing, genetically tractable single celled organism. Basic research in many eukaryotic cellular processes has been done on this organism, but NOT multicellular specific traits such as tissue differentiation, development, some types of cell signaling.

Saccharyomyces cerevisiae (yeast)

________ help proteins find each other.

Scaffolds

What are the two types of electron microscopes?

Scanning Electron Microscope Transmission Electron Microscope

What type of electron microscopy: High resolution of 3D specimens.

Scanning electron microscope

Local folding structures (alpha helices, beta sheets)

Secondary structure

What type of protein: Carry extracellular signals from cell to cell.

Signal proteins

Mitochondria and chloroplasts are most likely derived from engulfed _______.

bacteria

What are three functions of other amino acids within cells?

bacterial cell walls signaling antibiotic components

Beta sheets are often found in the core of proteins, but they don't have to be. An example is the _____-.

beta barrel

The active form of GTP can ____ and _______ other proteins.

bind and regulate

Allosteric regulators stabilize proteins in their preferred _______ state.

binding

Phosphorylation can change the shape and charge of proteins, which can: turn enzyme activity on/off alter binding between protein and ligand can create new docking sites (_____ sites) for multiple proteins

binding

Protein function can be disrupted by mutations in _______ or mutations that disrupt ______.

binding site; folding

A protein's stable conformation can be altered by _______. This can change or regulate the proteins function

binding to other molecules

Mitochondria often form long __________ networks.

branching

Transport vesicles are formed by _______.

budding

Cells are full of weak acids and bases. Among other roles, they can also help ______ the pH of cells and their organelles.

buffer

Disulfide bonds are covalent linkages between Cysteine side chains. ______ extracellular protein. Bond catalyzed in ER.

Stabilizes

What are two advantages of carbon-carbon bonds as the basis for organic chemistry?

Stable bonds Can form different shapes (chains, branched, rings)

Inhibit HMG-CoA reductase. Reduced cholesterol synthesis

Statins

Hydrophobic molecules based around 4 aromatic rings. Type of lipid.

Steroid

Provide mechanical strength to cells and tissues. Function depends upon binding to other proteins

Structural proteins

What type of protein: Provide mechanical support to cell and tissues.

Structural proteins

_______ molecules can make branched chains.

Sugar

_______ are a component of nucleotides.

Sugars

3D structure of entire polypeptide. Often consists of independently folding domains

Tertiary structure

In 1839, _______ found that all animal tissues are made of cells.

Theodor Schwann

Some proteins contain multiple polypeptides. What are two reasons why?

These proteins have complex functions These are large structural proteins

What do endoplasmic reticulum, golgi apparatus, transport vesicles, endosomes, lysosomes, and peroxisomes have in common?

They are all single-membrane bound organelles

What type of protein: Bind to DNA to switch genes on or off.

Transcription regulators

______ control is a key regulation step in regulating the production of proteins. It has fine control.

Transcriptional

_______ refers to the proteins that are actually expressed.

Transcriptome

What are the two types of electron microscopy?

Transmission and scanning

What type of electron microscopy: High resolution of sliced specimens

Transmission electron microscopy

What type of protein: Carry molecules or ions

Transport proteins

Carry membranes and other materials.

Transport vesicles

Three fatty acids bound to glycerol.

Triacylglycerol

_______ is used for concentrated food storage as hydrophobic fat droplets.

Triacylglycerol

_______ form large, spherical fat droplets in the cell cytoplasm.

Triacylglycerols

True or False: Allosteric regulation can be positive or negative.

True

True or False: Covalent bonds can be polar

True

True or False: Protein phosphorylation can activate or inactivate, it depends on the protein.

True

True or False: Proteins can have more than one binding site.

True

True or False: All cells share a common ancestry.

True. All cells arise from other cells (the third point of the cell theory)

What type of covalent modification: small protein attached to many target proteins

Ubiquitination

[Vertebrates/Invertebrates] are animals that are studied for organ development, embryonic development, and related cell signaling.

Vertebrates

maximum possible rate of reaction with non-limiting substrate reaction rate can be VERY fast. average = 1000 reactions/sec per enzyme

Vmax

Schwann's cell theory ignored what crucial question?

Where do cells come from?

What is saccharyomyces cerevisiae?

Yeast

Which model organism: transparent, accessible embryo many established mutant lines

Zebrafish

ATPases hydrolyze ATP. Stored energy is released. But it cannot remake ATP because this requires...

a huge energy input

What's the basic formula of sugars?

(CH₂O)ₙ

What is a carbonyl group? Is it nonpolar, reactive, or phosphate?

-C=O Reactive

If we are interested in human biology, why not just study humans? Give two reasons why model organisms are used.

1) Different questions can be more easily addressed in some systems. 2) Scientists can develop and share tools and resources for a given species

In the 1700s and 1800s, the scientific advances slowed down in the field of cell biology. Why (two reasons)?

1) Microscope resolution remains relatively low. 2) Studies are largely descriptive - observation and description without exploration of function

Theodor Schwann published the first cell theory with two points. What were they?

1) The cell is the basic unit of structure for all organisms 2) All organisms consist of one or more cells

Identify the key ideas (3) of the Cell Theory and understand how the work of multiple scientists in the 1800's (and earlier) contributed to the development of this theory.

1) The cell is the basic unit of structure for all organisms (developed by Schwann) 2) All organisms consist of one or more cells (developed by Schwann) 3) All cells arise only from pre-existing cells (developed by Virchow)

What are the ten nonpolar amino acids?

1. Alanine (Ala, A) 2. Glycine (Gly, G) 3. Valine (Val, V) 4. Leucine (Leu, L) 5. Isoleucine (Ile, I) 6. Proline (Pro, P) 7. Phenylalanine (Phe, F) 8. Methionine (Met, M) 9. Tryptophan (Trp, W) 10. Cysteine (Cys, C)

What are four ways that enzymes can speed up reactions?

1. Align 2 substrates in proper orientation for chemical reaction 2. Alter shape of substrate to favor the reaction 3. Alter electron distribution to favor the reaction 4. Form temporary covalent bonds with substrate to promote reaction Enzymes can do one or more of these.

What are the five polar, uncharged amino acids?

1. Asparagine (Asn, N) 2. Glutamine (Gln, Q) 3. Serine (Ser, S) 4. Threonine (Thr, T) 5. Tyrosine (Tyr, Y)

Sugars can also have structural and mechanical roles in addition to their energy roles. What are two of these structural/mechanical roles?

1. Cell wall support (cellulose, chitin) 2. Lubrication (mucus, slime)

What are the four requirements to be considered alive?

1. Distinct and independent from the surroundings. Highly organized interior, capable of homeostasis. 2. Grow, develop and reproduce themselves 3. Take energy and matter from the environment and transform it. 4. Interact with their environment and respond to stimuli

All cells share what four fundamental features?

1. Enclosed by a plasma membrane consisting of a lipid bilayer. 2. Can reproduce themselves and their internal components. 3. Shared basic biochemistry - same basic organic molecules (nucleic acids, proteins, etc) and conserved methods of producing, storing and using energy. 4. All cells encode their genetic information in DNA using shared genetic code genes encode proteins

The relationship between mitochondria and chloroplasts and the rest of the cell is symbiotic. Why? What benefits do either side receive?

1. Eukaryotes get more energy more efficiently 2. Mitochondria and Chloroplasts can't survive outside eukaryotes (many bacterial genes lost to nuclear genome)

What are the four types of large organic molecules? Of these four, what three are considered macromolecules?

1. Fats and membrane lipids 2. Polysaccharides, glycogen, and starch (macro) 3. Proteins (macro) 4. Nucleic aids (macro)

What are the three parts of a nucleotide?

1. Five carbon sugar 2. 1 or more phosphate groups 3. Nitrogen containing base

How do protein families arise (3 steps)?

1. Gene duplication can occur, so species now has two identical copies of a gene, but only one is essential for original function. 2. One of them can mutate = acquire slightly new function 3. These two gene products (once duplicates) are now members of a protein family

What are two advantages of human cell cultures?

1. Many cells can maintain their identity/function in cell culture 2. Can study some cell differentiation, effect of experimental treatments, etc.

What are the three uses/locations for proteins produced by the ER?

1. Membrane 2. Other organelles 3. Exported out of cell

What are two limitations to human cell cultures?

1. Not all behaviors are perfectly retained in tissue culture. 2. Many cell cultures are short lived. Not all cell types grow well in dishes.

The identity of sugar is determined by what three things?

1. Number of carbons 2. Type of carbonyl (-C=O) group 3. Orientation of hydroxyl (OH) groups

What are the three main functions of single membrane bound organelles?

1. Production and export of macromolecules 2. Import and digestion of macromolecules 3. Waste management

Mitochondria and chloroplasts are most likely derived from engulfed bacteria. What are three points of evidence that support this theory?

1. They have a double membrane like some bacteria 2. They have their own genomes and ribosomes. 3. Reproduce by binary fission

Enzyme function depends upon what two things?

1. binding affinity to substrate 2. rate they convert substrate to product after binding

Single celled organisms have many advantages as model organisms. Name three advantages.

1. inexpensive 2. straightforward and rapid genetics 3. good at growing = lots of material for biochemistry

One of the fundamental features that all cells share is that they all have the same basic biochemistry. What are two deeper explanations for what this means?

1. same basic organic molecules (nucleic acids, proteins, etc) 2. conserved methods of producing, storing and using energy

What are the three main functions of macromolecules?

1. structural functions 2. enzymatic functions 3. encode genetic information

How can you get proteins with new functions (two reasons)?

1. useful conformations are re-used. 2. minor sequence alterations modify function

Robert Hooke built own microscope in ______ observed small compartments in cork named them "cells" after the rooms in monasteries

1665

Phosphodiester bonds are formed by condensation reaction between _______ and _______.

5' phosphate and 3' hydroxyl

Nucleotide sequences are always given from __' to __' end.

5' to 3'

There are a vast number of possible protein sequences; only a small fraction are functional, stable proteins. That means that functional domains and proteins are conserved. An example of this conservation is ______, which are over 90% identical between yeast and humans.

90%

Retinal covalently binds to rhodopsin protein. It can absorb light and change shape (synthesized from vitamin ____).

A

What is Tribolium?

A flour beetle

What is arabidopsis?

A flower

What is Drosohila?

A fruit fly

Cell biologists and biochemists can use a variety of techniques to determine the three dimensional structure of a purified protein. Which of these is the best reason for determining a protein's structure? A) Knowing a protein's structure can contribute to our understanding of how the protein functions. B) You must know a protein's three dimensional structure to test its function in biochemical assays. C) Because scientists like to have pretty pictures for their publications. D) You can determine a protein's sequence from its structure.

A) Knowing a protein's structure can contribute to our understanding of how the protein functions.

Use the table of amino acids above (also found on page 120 of your text) to help you answer the following question. Which of these amino acids is most likely to be found in the hydrophobic core of a folded protein? A) alanine B) tyrosine C) aspartic acid D) arginine

A) alanine

Which of the following chemical groups doesn't contain polar bonds and therefore cannot form hydrogen bonds? A. Acetyl group (-CH₃) B. Amino group (NH₂) C. Hydroxyl group (OH) D. Carboxyl group (COOH)

A. Acetyl group (-CH₃)

Which statement concerning feedback inhibition is false? A. Feedback inhibition is difficult to reverse. B. Feedback inhibition can work almost instantaneously. C. Feedback inhibition regulates the flow through biosynthetic pathways. D. Feedback inhibition is a feedback system for controlling enzyme activity. E. In feedback inhibition, an enzyme acting early in a reaction pathway is inhibited by a later product of that pathway.

A. Feedback inhibition is difficult to reverse.

Which observation is not evidence supporting the model that mitochondria arose from bacteria engulfed by an ancestral eukaryote? A. Mitochondria can survive and multiply outside of eukaryotes. B. Mitochondria are surrounded by a double membrane. C. Mitochondria contain their own genomes. D. Mitochondria divide by binary fission.

A. Mitochondria can survive and multiply outside of eukaryotes.

What cellular process occurs in the cytosol of eukaryotic cells? A. Protein translation B. Energy production by cellular respiration C. DNA replication D. Degradation of cell waste and endocytosed materials

A. Protein translation B is wrong because energy production by glycolysis occurs in the cytosol.

Which four elements make up 96% of the weight of living organisms? Choose one: A. carbon, hydrogen, nitrogen, and oxygen B. carbon, calcium, oxygen, and nitrogen C. carbon, sodium, chloride, and oxygen D. carbon, phosphorus, sodium, and hydrogen E. carbon, oxygen, sodium, and hydrogen

A. carbon, hydrogen, nitrogen, and oxygen

Long polymers are made from single subunits in cells using a ___________ reaction, which ___________ water. Choose one: A. condensation; releases B. hydrolysis; uses C. condensation; uses D. hydrolysis; releases

A. condensation; releases

What role is NOT performed by the cytoskeleton? A. generating chemical energy for the cell B. generating contraction in muscle cells C. transporting organelles and molecules from one place to another in the cytoplasm D. pulling duplicated chromosomes to opposite poles in dividing cells E. controlling cell shape and cell movement

A. generating chemical energy for the cell

Which cellular component separates the DNA of eukaryotic cells from the cytoplasm? A. nuclear membrane B. cell wall C. smooth endoplasmic reticulum D. plasma membrane

A. nuclear membrane

Many proteins are regulated by the binding of GTP or GDP. Which form is the active state of the protein? A. the GTP-bound form B. the form to which no nucleotide is bound C. the form that is highest in concentration D. the GDP-bound form E. different forms for different proteins

A. the GTP-bound form A GTP-binding protein requires the presence of a tightly bound GTP molecule to be active. The active protein can shut itself off by hydrolyzing its bound GTP to GDP and inorganic phosphate (Pi), which converts the protein to an inactive conformation.

Which organism would be the most useful for studying how mutations that cause sudden death in young athletes can affect the development of the heart? A. zebrafish B. Escherichia coli C. Caenorhabditis elegans D. Arabidopsis thaliana E. Saccharomyces cerevisiae

A. zebrafish They are vertebrates, and the zebrafish has distinct advantages for studying aspects of development, including their quick gestation time and the fact that they are transparent for the first two weeks of life, making observation of cells and tissues easier.

Cellular respiration oxidizes ("burns") food to produce ______. It's highly efficient. It consumes oxygen and releases CO2.

ATP

Two nucleotides that are used for chemical energy.

ATP and GTP

________ drives motor proteins forward.

ATP hydrolysis

Motor proteins can shift their conformation to "walk" along the cytoskeleton. However, random conformational changes result in random movements. The movements are non-random due to the ______.

ATP-ase

What type of enzyme: Hydrolyzes ATP. Examples include motor proteins such as myosin and membrane transport proteins such as sodium pump.

ATPase

______ hydrolyze ATP. Stored energy is released.

ATPases

What are the four types of amino acids?

Acidic Basic Uncharged polar Nonpolar

Very polar molecules that can donate H+ ion in an aqueous environment

Acids

The highly dynamic portion of the cytoskeleton.

Actin

Which type of cytoskeleton: Used in cell structure, muscle contraction, cell movement and cytokinesis (division).

Actin

What are the three types of cytoskeleton?

Actin Microtubule Intermediate filaments

binding site that catalyzes chemical transformation of substrate

Active site

Cells store usable energy in this molecule's phosphoanhydride bonds.

Adenosine Triphosphate (ATP)

Rudolf Virchow added a third critical point to Schwann's cell theory. What was this third point?

All cells arise only from pre-existing cells

have more than one (slightly different) stable conformation. Conformation dependent upon ligand binding at regulatory site

Allosteric proteins

What are two interactions with other molecules that can directly regulate the activity of proteins?

Allosteric regulation GTP/GDP binding

Forms a rigid cylinder. Has a hydrophilic backbone is inside. All side chains are extending outwards.

Alpha helix

What are the two main types of secondary structure?

Alpha helix Beta sheet

Cells in an organism all have the same genome. How can cells be so different?

Although they have the same genome, different cells can express different genes

_______ alone is sufficient to dictate folding

Amino acid sequence

The first to describe living cells including protozoa, red blood cells, bacteria, algae. Occurred in the late 1600s.

Antonie van Leeuwenhoek

Flowering plant that is a model for crop plants (seed development and germination, regulation of flowering, stress responses). Rapid growth and simple genetics (for a plant).

Arabidopsis thaliana

What are the three basic (positively charged) amino acids?

Arginine (Arg, R) Lysine (Ls, K) Histidine (His, H)

What are the two acidic (negatively charged) amino acids?

Aspartic acid (Asp, D) Glutamic acid (Glu, E)

Which of these is a component of the cell theory, which was established in the late 1800s through the work of several cell biologists? A) All cells contain a nucleus. B) All cells arise only from pre-existing cells C) All cells are the same size. D) All organisms consist of more than one cell

B) All cells arise only from pre-existing cells

I discussed the mechanism by which lysozyme catalyzes the hydrolysis of polysaccharide chains in bacterial cell walls. You decide to mutate the gene encoding lysozyme so that Glu35(glutamic acid) in the active site is replaced with the large, nonpolar amino acid tryptophan. What would you predict is the most likely result? A) Substrate binding would be decreased; Catalytic activity would be unaffected. B) Substrate binding would be decreased; Catalytic activity would be decreased. C) Substrate binding would be increased; Catalytic activity would be decreased. D) Substrate binding would be increased; Catalytic activity would be unaffected.

B) Substrate binding would be decreased; Catalytic activity would be decreased.

Nucleotides can form long polymers called nucleic acids. Which of these statements about nucleic acids is FALSE? A) Nucleic acids have a polarity, with a 5' end and a 3' end. B) The peptide bonds between nucleotides are broken by a hydrolysis reaction. C) Nucleic acids are formed from nucleotides by a condensation reaction. D) DNA and RNA are the two types of nucleic acids.

B) The peptide bonds between nucleotides are broken by a hydrolysis reaction.

Some cytoplasmic proteins are multisubunit complexes containing more than one polypeptide chain. These complexes are held together by what type of bonds/interactions between the polypeptide chains? A) both peptide bonds and non-covalent bonds B) non-covalent bonds C) glycosidic bonds D) peptide bonds, glycosidic bonds and non-covalent bonds E) peptide bonds

B) non-covalent bonds

Many lipids are amphipathic and are capable of forming lipid bilayers. Which of these lipids is not an essential component of cell membranes? A) phospholipids B) triacylglycerol C) glycolipids D) cholesterol

B) triacylglycerol

An oxygen atom, with six electrons (of a possible eight) in its outer electron shell, has the capacity to form a maximum of how many covalent bonds? Choose one: A. 6 B. 2 C. 8 D. 3 E. 4

B. 2 An oxygen atom, with six electrons (of a possible eight) in its outer electron shell, has the capacity to form a maximum of two covalent bonds. Oxygen will form covalent bonds with other atoms to fill its outer shell, which can accommodate two additional electrons: 6 + 2 = 8.

You are interested in studying how mitochondria interact with their host cells. Which of these model systems would not be an appropriate choice? A. Drosophila (fruit fly) B. E. coli (bacteria) C. Arabidopsis thaliana (flowering plant) D. M. musculus (mice) E. S. cerevisiae (yeast)

B. E. coli (bacteria)

Some proteins are multisubunit complexes containing more than one polypeptide chain. These complexes can potentially be held together by what type of bonds/interactions between the polypeptide chains? (choose one or more) A. Peptide bonds B. Electrostatic interactions C. Glycosidic bonds D. Disulfide bonds E. Hydrogen bonds

B. Electrostatic interactions. D. Disulfide bonds E. Hydrogen bonds

You are interested in mitochondrial replication by binary fission. For your experiments, you need to observe this process in living cells. Which type of microscope would be the best choice? A. Transmission electron microscope B. Fluorescent light microscope C. Scanning electron microscope

B. Fluorescent light microscope

Glucose has a molecular weight of 180 g and sodium chloride has a molecular weight of 58 g. Which of the following is true? A. One mole of glucose contains more molecules than one mole of sodium chloride. B. One mole of glucose and one mole of sodium chloride each contain the same number of molecules. C. One mole of glucose and one mole of sodium chloride each weight the same amount. D. One mole of glucose weighs less than one mole of sodium chloride.

B. One mole of glucose and one mole of sodium chloride each contain the same number of molecules.

You mutate the gene encoding lysozyme so that Glu35 (glutamic acid) in the active site is replaced with the large, nonpolar amino acid tryptophan. What would you predict is the most likely result? A. Substrate binding would be decreased; Catalytic activity would be unaffected B. Substrate binding would be decreased; Catalytic activity would be decreased C. Substrate binding would be increased; Catalytic activity would be unaffected D. Substrate binding would be increased; Catalytic activity would be decreased

B. Substrate binding would be decreased; Catalytic activity would be decreased

When comparing liver cells and kidney cells within an organism, many differences can be observed and documented. Which of following is not a difference between liver cells and kidney cells in the same animal? A. The different cells have different roles in the body. B. The different cells have different DNA. C. The different cells produce different proteins. D. The different cells are generated during the animal's development. E. The different cells express different genes.

B. The different cells have different DNA. Liver cells and kidney cells have the same genome, but they use the encoded information differently, expressing different genes and producing different proteins.

Which of the following is true of an enzyme that is operating at its maximum rate? A. Half of the substrate-binding sites on the enzyme molecules are occupied. B. The substrate-binding sites on the enzyme molecules are fully occupied. C. Increasing the substrate concentration will increase the turnover number. D. The concentration of substrate is equal to the KM. E. The concentration of substrate is half of the KM.

B. The substrate-binding sites on the enzyme molecules are fully occupied. When an enzyme is operating at Vmax, the active sites of all of the enzyme molecules in the sample are occupied by substrate. At this point, the rate of product formation depends only on how rapidly the substrate molecules can undergo the chemical reaction that converts them into product.

Which of the following statements comparing a human liver cell to a human neuron is true? A. The two types of cells contain different genes in their genomes and don't express identical sets of proteins. B. The two types of cells contain identical genes in their genomes but don't express identical sets of proteins. C. The two types of cells contain different genes in their genomes but express identical sets of proteins. D. B. The two types of cells contain identical genes in their genomes and express identical sets of proteins.

B. The two types of cells contain identical genes in their genomes but don't express identical sets of proteins.

What do the segments of a transmembrane protein that cross the lipid bilayer usually consist of? A. a β sheet with mostly polar side chains B. an α helix with mostly nonpolar side chains C. an α helix with mostly polar side chains D. a β sheet with alternating polar and nonpolar side chains

B. an α helix with mostly nonpolar side chains

What is the definition of a protein-binding site? A. a pocket on a protein where a small molecule can be covalently attached and thus modify the protein B. any region on a protein's surface that interacts with another molecule through noncovalent bonding C. the region of the cell where proteins are assembled based on information from the genetic code D. the portion of a protein that attaches to the cell membrane and tethers the protein as a peripheral membrane protein

B. any region on a protein's surface that interacts with another molecule through noncovalent bonding

Which type of bond is the strongest in cells? Choose one: A. ionic B. covalent C. hydrogen

B. covalent

Which of the following occurs by bringing nonpolar surfaces together to exclude water? Choose one: A. hydrogen bonds B. hydrophobic forces C. electrostatic attractions D. Van der Waals attractions

B. hydrophobic forces

Which of these cannot be resolved with a conventional light microscope? A. cell nucleus B. ribosome C. embryonic cell D. mitochondrion E. bacterium

B. ribosome It's too small

In a cytosolic folded protein, what orientation and/or interaction do the hydrophobic amino acids tend to have? Choose one or more: A.They are exposed on the outside of the protein. B.They are interacting with other nonpolar amino acids. C.They are clustered near the N-terminus of the protein. D.They are tucked away inside the protein.

B.They are interacting with other nonpolar amino acids. D.They are tucked away inside the protein.

You have developed a promising anti-cancer agent, but it has poor solubility in water. Which of the following changes should improve water solubility? Choose one or more: A.increasing the size of the drug B.adding a hydroxyl group C.adding a methyl group D.adding a carboxyl group

B.adding a hydroxyl group (OH) D.adding a carboxyl group (COOH)

You are a biologist interested in studying how eukaryotic cells obtained their unique features during their evolution from a prokaryotic ancestor. Which cellular features, unique to eukaryotes, might you focus on? Choose one or more: A.the cell membrane B.mitochondria C.the nucleus D.ribosomes

B.mitochondria C.the nucleus

Molecules that accept a H+ ion from an aqueous environment.

Bases

Region of a protein that interacts specifically with another molecule. Typically very specific.

Binding site

Region of protein that interacts with specific molecule

Binding site

Examining function of molecules and organelles (in vitro)

Biochemistry

The study of the chemistry of cell structure and function.

Biochemistry

Coenzymes are small organic molecules that help catalyze reactions. One example is _______ which is used many enzymes that transfer carboxyl groups.

Biotin (vitamin B7)

Not all traits that are similar are homologous. Give an example of this.

Bird wings and insect wings are similar, but they are not homologous because they didn't originate from the same ancestor.

The most efficient way in the body to break covalent bonds.

By using enzymes.

Which of these statements about protein domains is FALSE? A) A protein domain could contain both alpha helices and beta sheets. B) Protein domains can have distinct functions. C) All proteins contain more than one domain. D) Protein domains can fold independently of the rest of the protein.

C) All proteins contain more than one domain.

Non-covalent interactions are much weaker than covalent bonds, but they are critical for the stable folding of proteins as well as for the interaction of proteins with their ligands. Why is this? A) Once formed, non-covalent bonds can only be broken by enzyme catalyzed hydrolysis. B) All amino acid side chains are capable of forming hydrogen bonds. C) Although weak individually, the combination of many weak non-covalent bonds together can create strong, stable interactions. D) Although weak in a vacuum, electrostatic interactions are very strong in aqueous environments.

C) Although weak individually, the combination of many weak non-covalent bonds together can create strong, stable interactions.

Which of the following is NOT evidence that chloroplasts are derived from engulfed bacteria? A) Chloroplasts contain their own ribosomes. B) Chloroplasts reproduce by binary fission. C) Chloroplasts can survive on their own, outside of plant cells. D) Chloroplasts contain DNA that encode some, but not all, of their proteins.

C) Chloroplasts can survive on their own, outside of plant cells.

Which organelle is the site of lipid synthesis and some protein synthesis. A) Endosomes B) Lysosomes C) Endoplasmic Reticulum D) Golgi apparatus

C) Endoplasmic Reticulum

Some drugs, such as the anti-cancer drug Gleevec, are competitive inhibitors of enzymes. Gleevec specifically targets a kinase that is activated in certain types of cancer. Given what we learned about competitive inhibitors, how does Gleevec function? A) Gleevec binds to a regulatory site on the kinase and inhibits its activity. B) Gleevec directly blocks transcription of the kinase. C) Gleevec binds to the active site of the kinase and interferes with substrate binding. D) Gleevec binds to the active site of the kinase and reduces the enzyme's Vmax.

C) Gleevec binds to the active site of the kinase and interferes with substrate binding.

The cell's cytoskeleton is made of several different types of protein filament. Which type of cytoskeleton functions solely to confer mechanical strength and stress resistance to animal cells? A) Collagen fibrils B) Actin filaments C) Intermediate filaments D) Microtubules

C) Intermediate filaments

Glucose has a molecular weight of 180 g and NaCl as a molecular weight of 58 g. Which of the following statements is true? A) One mole of glucose weights less than one mole of NaCl.. B) One mole of glucose and one mole of NaCl each weigh the same amount. C) One mole of glucose and one mole of NaCl each contain the same number of molecules. D) One mole of glucose contains more molecules than one mole of NaCl.

C) One mole of glucose and one mole of NaCl each contain the same number of molecules.

Which of these statements about protein phosphorylation is FALSE? A) Addition of a phosphate group to a protein can create new binding sites on the protein.. B) Some proteins are activated by phosphorylation, while some proteins are inactivated by it. C) Phosphorylation is reversible, because phosphatases add phosphate groups to proteins and kinases remove them. D) Phosphorylation adds a highly charged group and can alter the target protein's 3D conformation.

C) Phosphorylation is reversible, because phosphatases add phosphate groups to proteins and kinases remove them.

Plasmin and cathepsin G are both serine proteases. Which of these statements about these two proteins is FALSE? A) They are homologs. B) They are members of the same protein family. C) They are both enzymes that catalyze the synthesis of serine. D) Their three dimensional structures are similar to that of chymotrypsin.

C) They are both enzymes that catalyze the synthesis of serine.

Which of the following chemical groups is not capable of forming hydrogen bonds? A) carboxyl group (-COOH) B) amino group (-NH2) C) acetyl group (-CH3) D) hydroxyl group (-OH)

C) acetyl group (-CH3)

A deoxyribose sugar [can/cannot] bind.

cannot

ATP [can/cannot] bind.

cannot

Louis Pasteur proved that cells...

cannot arise spontaneously.

The process of _______, which occurs within chloroplasts, is essential for all life on earth.

carbon fixation

NADH and NADPH both have a ______ that is critical for their function.

carbon ring

Organic molecules are built around _______-_______ bonds.

carbon-carbon

Coenzymes are small organic molecules that help catalyze reactions. One example is Biotin (vitamin B7) which is used many enzymes that transfer _______ groups.

carboxyl

These are the two parts of fatty acids: Hydrophilic ______ group head Hydrophobic hydrocarbon tail

carboxyl

The _______ of fatty acids is reactive. It can form covalent bonds with other groups.

carboxyl group

With metal ions assisting enzymes, ________ remove the last amino acid of polypeptide chains. Requires a tightly bound zinc ion

carboxypeptidases

Lee Hartwell won the Nobel prize in 2001 for working with yeast and discovering...

cell cycle control

p53 transcriptional regulator is a tumor suppressor. What are three things it controls/helps control?

cell cycle control DNA damage response regulation of programmed cell death

In the 1700s and 1800s, the scientific advances slowed down in the field of cell biology. The studies were largely descriptive. However, these studies described the nucleus, mitochondria, and chromosomes. The process of ______ was also observed.

cell division

Some bonds are high energy. These bonds are essential for cell ______.

cell metabolism

In plants, cells are supported by the ______.

cell wall

Retinal covalently binds to rhodopsin protein. It can absorb light and _______ (synthesized from vitamin A).

change shape

Electrostatic interactions occur between fully or partially ______ groups.

charged

Atoms can fill their electron shell via ______.

chemical bonds

Neutrons affect an atom's stability but not its...

chemical properties

Chloroplasts are surrounded by a double membrane. It has separate internal membranes. The internal membranes contain _______ and is the site of ________.

chlorophyll; photosynthesis

Nucleotides form ______ (small molecules that help enzymes function).

coenzymes

All polymers are created by ______ reactions.

condensation

Peptide bonds are created by _______ reactions

condensation

Phosphodiester bonds are formed by _______ reaction between 5' phosphate and 3' hydroxyl.

condensation

Glycosidic bonds are covalent bonds between hydroxyl groups formed by _______ reactions. This reaction is energetically unfavorable.

condensation (releases water)

A ______ reaction joins two monomers together, releasing water. A ______ reaction uses water to split the bond that joins two subunits of a polymer.

condensation; hydrolysis

Allosteric regulation, GTP/GDP binding, protein phosphorylation, and other covalent modifications all affect protein activity by altering protein _______, protein _____, or protein ______.

conformation, location, or stability

Linking energetically favorable reaction to a _______ is used by many other types of proteins.

conformational change

There are a vast number of possible protein sequences; only a small fraction are functional, stable proteins. That means that functional domains and proteins are ______.

conserved

Exocytosis and endocytosis is a [constant/periodic] process.

constant

Beta sheets are often found in the ____ of proteins, but they don't have to be. An example is the beta barrel.

core

Robert Hooke built own microscope in 1665 observed small compartments in _____ named them "cells" after the rooms in monasteries

cork

Disulfide bonds are _____ linkages between Cysteine side chains. Stabilizes extracellular protein. Bond catalyzed in ER.

covalent

If two atoms share electrons, it is a _______ bond.

covalent

Polymers are held together by _____ bonds.

covalent

Protein degradation is regulated by _______ modification in a process called poly-ubiquitination. It targets proteins for degradation by the proteasome

covalent

The carboxyl group of fatty acids is reactive. It can form ______ bonds with other groups.

covalent

Retinal ______ binds to rhodopsin protein. It can absorb light and change shape (synthesized from vitamin A).

covalently

Nucleotides can also be signaling molecules such as ______.

cyclic AMP (cAMP)

Disulfide bonds are covalent linkages between __(amino acid)___ side chains. Stabilizes extracellular protein. Bond catalyzed in ER.

cysteine

In prokaryotes, their DNA is in the...

cytoplasm

In prokaryotes, transcription and translation occurs in the...

cytoplasm

Membrane bound organelles, cytoskeleton, and cytosol are all located in the...

cytoplasm

Triacylglycerols form large, spherical fat droplets in the cell ___(organelle)___.

cytoplasm

Motor proteins can shift their conformation to "walk" along the _______.

cytoskeleton

Most protein translation, glycolysis, and signal transduction all occur in the...

cytosol

The ______ is essentially "everything else" in the cytoplasm.

cytosol

Chemical modification of inhibitor often improve its performance. This is called drug _______.

development

A ______ is formed by interaction between a single, identical binding site on each monomer.

dimer

Identify an enzyme critical to disease of interest. Screen libraries of small molecules for inhibitors. These steps are known as drug ______.

discovery

Tertiary structures often have one or more ______.

domains

Alternating ______ bonds have resonance electrons. These are shared by more than two atoms and form very stable bonds.

double

The formation of protein families depends on gene ______.

duplication

Bonds are polar if the two atoms have different values for _______.

electronegativity

In endocytosis, transport vesicles buds off plasma membrane. _______ is used as a sorting station. The lysosome is used for digestion of waste and endocytosed molecules.

endosomes

Phosphorylation can change the shape and charge of proteins, which can: turn _____ activity on/off alter binding between protein and ligand can create new docking sites (binding sites) for multiple proteins

enzyme

All polymers are created by condensation reactions and broken by hydrolysis reactions. Both of these reactions are...

enzyme catalyzed

Regulating pH is critical for cell function because many ______ and reactions are pH dependent.

enzymes

The structure of a protein must be determined...

experimentally

In endocytosis, transport vesicles buds off plasma membrane. Endosomes is used as a sorting station. Lysosomes is used for digestion of waste and endocytosed molecules. The output (what was digested by the lysosome) can be ______ or ______.

exported or reused

In animals, cells are surrounded by an _______.

extracellular matrix

The main molecules that are exported by exocytosis are ________ that were sorted in Golgi apparatus.

extracellular proteins/lipids

Triacylglycerols form large, spherical _______ in the cell cytoplasm.

fat droplets

Glycosidic bonds are covalent bonds between hydroxyl groups broken by hydrolysis reactions. This reaction is energetically [favorable/unfavorable].

favorable

Some structural proteins are _____, like keratin and collagen. Individual polypeptides can form long, elongated structure

fibrous

Polypeptide backbones are very ______. They can potentially fold into innumerable possible conformation

flexible

Mitochondria are surrounded by a double membrane. The inner membrane is highly ______. These folds are the site of cellular respiration.

folded

Hydrogen bonds are critical for protein ______.

folding

Triacylglycerol is used for concentrated ______ as hydrophobic fat droplets.

food storage

Steroids are hydrophobic molecules based around __(#)___ aromatic rings. Type of lipid.

four

The hemoglobin protein is made up of __(#)___ polypeptides.

four

Atoms are most stable if their electron shells are...

full

Geometry of bonds influences 3D conformation of macromolecules. The shape and flexibility of the macromolecule influences _____

function

The sequence of macromolecules is essential for their function. It's determined by ______ for proteins and nucleic acids. It's determined by ______ for polysaccharides.

genetic information; action of enzymes

Cells in an organism all have the same ______, but they can express different sets of genes (their _______).

genome; transcriptome

While structural proteins like keratin and collagen are fibrous, some structural proteins are ______.

globular

Glucose polymers are used for energy storage. This is _____ in animals and _____ in plants

glycogen; starch

Km is the substrate concentration that yields ______.

half Vmax

Eukaryotes are defined by...

having a nucleus

oxygen carrying proteins in red blood cells. Require Fe4+ containing _____ groups

heme

Polysaccharides are very stable, so spontaneous hydrolysis is very rare (due to _______).

high activation energy

These are the two parts of fatty acids: Hydrophilic carboxyl group head Hydrophobic ______ tail

hydrocarbon

DNA base pairing occurs via ______ bonds.

hydrogen

One Dalton ≈ one ______ atom.

hydrogen

Secondary structure is stabilized by _______ bonds formed by polypeptide backbone not by side chains bonds.

hydrogen

There are ______ bonds between segments of a β sheet.

hydrogen

All polymers are broken by ______ reactions.

hydrolysis

ATPases _______ ATP. Stored energy is released.

hydrolyze

Polar side chains can form hydrogen bonds with water while the nonpolar side chains are packed into the _______ core region.

hydrophobic

Hydrophobic molecules are excluded from water's hydrogen bond network, so they're forced together. This force is called...

hydrophobic force

Glycosidic bonds are covalent bonds between ______ groups formed by condensation reactions. This reaction is energetically unfavorable.

hydroxyl (OH)

probes for mRNA in fixed samples. One gene at a time

in situ hybridization

GTP binding protein remains [active/inactive] until it can exchange the GDP for GTP

inactive

What is a competitive inhibitor's effect on Km?

increase Km (decrease affinity)

If two atoms transfer electrons, it is a ______ bond.

ionic

If ATP hydrolysis is linked to a conformational change, then it is _______.

irreversible

Protein degradation by poly-ubiquitination [is/is not] reversible.

is not

A ______ will remove a phosphate from ATP and add it to the protein.

kinase

In regulating protein phosphorylation, it is important to regulate ______ and ______.

kinases and phosphatases

Prokaryotes are defined by...

lacking a nucleus

Mutations that substitute similar amino acids have [more/less] effect than mutations than change amino acid type (acidic, basic, uncharged polar, or nonpolar).

less

Allosteric proteins have more than one (slightly different) stable conformation. Conformation dependent upon...

ligand binding at a regulatory site

One of the fundamental features that all cells share is that they are all enclosed by a plasma membrane consisting of a _______.

lipid bilayer

The shape of glycolipids and phospholipids and their amphipathic nature allow them to form _______.

lipid bilayers

Robert Hooke built own microscope in 1665 observed small compartments in cork named them "cells" after the rooms in monasteries. An important thing to remember is that these cells were not...

living

Protein sequences encoded by genes and carried to ribosomes by _____.

mRNA

Sugars are involved in modifying certain proteins and lipids. These can become a protective layer on cell surfaces or cell surface ______.

markers

A dalton is a unit of ____.

mass

Lipid attachment drives proteins to anchor in ______

membrane

One of the reasons why people believe mitochondria and chloroplasts are derived from engulfed bacteria is that they have a double membrane. Related to this fact is that their ________ are more similar to bacteria than eukaryotes.

membrane proteins

The sugar molecules and oxygen produced by photosynthesis are used by ________.

mitochondria

signaling protein that toggles between on and off state

molecular switch

1 mole always has the same number of ______.

molecules

The triacylglycerol in animals is [more/less] saturated than the one in plants.

more

With an increased Km due to competitive inhibitors, _______ is required to reach the same reaction rate.

more substrate

Polypeptide backbones are very flexible. They can potentially fold into innumerable possible conformation. However, proteins have a ______ conformation.

most stable

ATP hydrolysis drives ______ forward.

motor proteins

Yeast has all the advantages of fast-growing, genetically tractable single celled organism. Basic research in many eukaryotic cellular processes has been done on this organism, but NOT ______ specific traits such as tissue differentiation, development, some types of cell signaling.

multicellular

The number of mitochondria vary depending on...

needs of the cell

Sequence of macromolecule information determines final stable 3-D conformation. This is mediated by _______ interactions within macromolecule.

non-covalent

The nucleus is surrounded by the _______, which is two concentric lipid bilayers.

nuclear envelope

ATP is an example of a ____(macromolecule)___.

nucleotide

An α helix forms a rigid cylinder. Has a hydrophilic backbone is inside. All side chains are extending ______.

outwards

Cellular respiration _______- ("burns") food to produce ATP. It's highly efficient. It consumes oxygen and releases CO2.

oxidizes

Photosynthesis is the harvesting of light energy to produce sugar molecules (energy source). It releases _______.

oxygen

Cellular respiration oxidizes ("burns") food to produce ATP. It's highly efficient. It consumes ______ and releases ______.

oxygen; CO₂

An α helix forms a rigid cylinder. Has a hydro[philic/phobic] backbone is inside. All side chains are extending outwards.

philic

Cells store usable energy in ATP's _______ bonds.

phosphoanhydride

Nucleotides are also a source of -OPO₃²⁻ groups for _______ reactions.

phosphorylation

A ______ bond occurs when electrons are not shared equally.

polar

Non-covalent bonds stabilize protein folding. Hydrogen bonds are very common because amino acids have many _____ groups.

polar

The aqueous environment influences folding. The _____ and ______ amino acids segregate in folded protein

polar and nonpolar

Hydrogen bonds can form between molecules with [polar/nonpolar] [ionic/covalent] bonds.

polar covalent

Protein degradation is regulated by covalent modification in a process called _______. It targets proteins for degradation by the proteasome

poly-ubiquitination

mRNA is read by ribosomes, which catalyze _______.

polymerization

Secondary structure is stabilized by hydrogen bonds formed by _______ not by ______ bonds.

polypeptide backbone not by side chains

The active site on lysozymes is highly specific for _______.

polysaccharides

Protein degradation is regulated by covalent modification in a process called poly-ubiquitination. It targets proteins for degradation by the _______

proteasome

Sugars are involved in modifying certain proteins and lipids. These can become a ______ on cell surfaces or cell surface markers.

protective layer

ATP hydrolysis can control ________.

protein activity/function

Phosphorylation can change the shape and charge of proteins, which can: turn enzyme activity on/off alter binding between ____ and _____ can create new docking sites (binding sites) for multiple proteins

protein and ligand

The ________ control has a rapid off switch. It is not quickly reversed.

protein degradation control

Amino acid function depends upon their side chains. Side chains can affect ______ and _______.

protein folding and protein's interactions with binding partners/substrates.

There are 20 common amino acids used in ______ that are shared across all species.

protein synthesis

A different transcriptome will result in a different set of expressed ______.

proteins

The nucleus contains DNA and ______. These replicate DNA, transcribe DNA, and organize and condense chromosomes.

proteins

The sequence of macromolecules is essential for their function. It's determined by genetic information for ______ and ______. It's determined by action of enzymes for _______.

proteins and nucleic acids; polysaccharides

The number of ____ and ______ determine the atom's chemical properties.

protons and electrons

Motor proteins can shift their conformation to "walk" along the cytoskeleton. However, random conformational changes result in ______ movements

random

According to Charles Darwin and his theory of evolution from 1859, _______ and ________ have created the enormous diversity of life today.

random variation and natural selection

The carboxyl group of fatty acids is ______. It can form covalent bonds with other groups.

reactive

When thinking about the relationship between model organisms and human biology, we must remember that all cells are...

related

A condensation reaction joins two monomers together, [using/releasing] water. A hydrolysis reaction [uses/releases] water to split the bond that joins two subunits of a polymer.

releasing; uses

Alternating double bonds have _____ electrons. These are shared by more than two atoms and form very stable bonds.

resonance

Protein phosphorylation adds a highly charged phosphoryl group to proteins. Causes a conformational change that alters function. It is [reversible/irreversible].

reversible

Retinal covalently binds to _______ protein. It can absorb light and change shape (synthesized from vitamin A).

rhodopsin

Protein sequences encoded by genes and carried to ______ by mRNA.

ribosomes

Protein synthesis in the ER occurs on surface bound cytosolic ______.

ribosomes

mRNA is read by ______, which catalyze polymerization.

ribosomes

Sugars form _____ in water.

rings

Sugars can share same chemical formula but have very different ______ within cell.

roles

Robert Hooke built own microscope in 1665 observed small compartments in cork named them "cells" after the...

rooms in monasteries

Amino acid sequence alone is sufficient to dictate folding. However, the right conditions with regards to ______, ______, and ______ is required.

salt concentration, pH, and aqueous environment

Chaperones increase efficiency and reliability, but the ________ still determines what correct conformation should be.

sequence

Some proteins are expressed in all or most cells. These are required for _______ processes.

shared

Amino acid function depends upon their ______.

side chains

Amino acid side chains can't catalyze all necessary reactions, so some enzymes use ______ during catalysis

small molecules

Some proteins are only expressed in certain cells. These are required for _______ processes.

specialized

Like folding, assembly of subunits can occur _______.

spontaneously

Neutrons affect an atom's _____ but not its chemical properties.

stability

Disulfide bonds ______ proteins.

stabilize

In coiled coils, the side chains _______ interactions between strands.

stabilize

Alternating double bonds have resonance electrons. These are shared by more than two atoms and form very [stable/unstable] bonds.

stable

A smaller Km means there is [stronger/weaker] binding.

stronger

Keratin filaments in cytoskeleton and collagen fibrils of the extracellular matrix are two types of _______ proteins.

structural

The sequence of amino acids determines a protein's _____ and ______

structure and function

Km is the _______ concentration that yields half Vmax.

substrate

Enzymes bind and act on ______

substrates

The _______ and ______ produced by photosynthesis are used by mitochondria.

sugar molecules and oxygen

Proteins should only be made when...

their function is required (or will be required)

Multicellular organisms organize most cells into _____.

tissues

Richard Kornber won the Nobel prize in 2006 for working with yeast to discover...

transcription regulation

Schwann published his original cell theory with __(#)___ points.

two

Glycosidic bonds are covalent bonds between hydroxyl groups formed by condensation reactions. This reaction is energetically [favorable/unfavorable].

unfavorable

Irreversible steps that lead to a conformational change in motor proteins make movement ________.

unidirectional

Mitochondria produce _______ energy.

usable

At short distances, atoms are attracted due to fluctuating e- charges. These are very weak individually, but can involve all atoms in a macromolecule.

van der Waals interactions

Randy Shekman won the Nobel prize in 2013 for his work on yeast to discover...

vesicle transport

Electrostatic interactions can contribute to strong interactions if there are many of them and if ________ is excluded.

water

Ionic bonds are extremely weak bonds when in _____.

water

Resolution of light microscopes is limited by _______ of visible light.

wavelength

Cells are full of [strong/weak] acids and bases.

weak

Electrostatic interactions are [stronger/weaker] when in water.

weaker It disrupts interactions

With metal ions assisting enzymes, carboxypeptidases remove the last amino acid of polypeptide chains. Requires a tightly bound ______ ion

zinc

_____(structure)____ is found in many transmembrane proteins.

α helices

______ can form stable coiled coils.

α helices