BIOL 101 Exam 1: Chapters 1,4, and 5

what is a valid testable prediction based on the above hypothesis?

incubation of any crocodile egg at 32 decrees celsius will result in a male crocodile

simple diffusion

is a spontaneous process

an iv solution must be _________ to a persons red blood cells to prevent injury to the cells

isotonic

acetylcholine binds this membrane protein, which subsequently opens to allow sodium to enters the cell. acetylcholine exerts its effect on what type of transport protein

ligand-gated channels

which is not found in a bacteria

lysosomes

which organelle uses catalase to complete the following reaction: 2H2O2 -> 2H2O + O2

peroxisome

the process by which a macrophage (white blood cell) consumes bacterium is

phagocytosis

chloroplasts are found in

plants and algae

water diffuse through certain organs such as the kidneys and bladder much faster. what accounts for this?

presence of aquaporin channels

which of the following would make the a membrane more fluid

increase in cholesterol

Flagellum

A long, whiplike structure that helps a cell to move

scientific method

A series of steps followed to solve problems including observation, question, formulating a hypothesis, prediction, experiment, collect data, conclusion, and peer review publication

Describe in detail 4 examples that show how a faulty plasma (cell) membrane is the cause of many medicals conditions. (See your PP slide called membrane protein diversity to prepare for this possible question.

Channel protein issues- Cystic fibrosis is caused by faulty chloride (Cl) channel; a thick mucus collects in airways and in pancreatic and liver ducts. Carrier protein issues- The inability of some persons to use energy for sodium-potassium transport has been suggested as the cause of their obesity. Enzymatic protein catalyzes a specific reaction. The membrane protein, adenylate cyclase, is involved in ATP metabolism. Cholera bacteria release a toxin that interferes with the proper functioning of adenylate cyclase; sodium ions and water leave intestinal cells, and the individual dies from severe diarrhea. Cell recognition protein issues- The MHC glycoproteins are different for each person, so organ transplants are difficult to achieve. Cells with foreign glycoproteins are attached by blood cells responsible for immunity.

function of smooth ER

Detoxification and metabolism of multiple molecules

With regard to bringing solutes into the cell across the plasma membrane, discuss the advantages and disadvantages of diffusion, facilitated diffusion, active transport, and endocytosis.

Diffusion does not require the synthesis of a protein and does not use energy. However, it only applies to hydrophobic solutes that can cross the membrane. Facilitated diffusion requires the synthesis of a protein, but the transport process doesn't require energy. Both diffusion and facilitated diffusion can only transport solutes downhill. By comparison, active transport can transport solutes against a gradient, but it does require the input of energy. Finally, an advantage of endocytosis is that it can transport large solutes and even things like bacteria into the cell.

Among mammals, give two examples of how the tail has been modified and has different purposes.

In monkeys the tail has been modified to grasp onto things such as tree branches. In skunks the tail is modified with a bright stripe; the tail can stick up and act as a warning signal to predators. In cattle the tail has long hairs and is used to swat insects.

Ribosomes

Makes proteins

Describe in detail the 7 steps involved in the milk story we talked about in class

Milk protein genes are copied to mRNA. mRNA exits through nuclear pore. At ribosomes on surface of rough ER, information in mRNA is used to produce milk proteins. Enzymes in smooth ER manufacture lipids. Milk proteins and lipids are packaged into vesicles from both rough and smooth ER for transport to Golgi. In Golgi, proteins and lipids are processed and packaged for export out of cell. Proteins and lipids are released from cell when vesicles fuse with cell membrane.

what process best characterizes Na+ movement from the blood (low Na concentration) into the kidney cells (high Na concentration)

Na movement involves active transport

If a heavy metal labeled the hydrophobic tails rather that the polar head groups (as osmium tetroxide does), do you think you would see a bilayer (the is, a railroad track) under the TEM?

Probably not. The hydrophobic tails of both leaflets touch each other, so the heavy metal would probably show a single, thick dark line. Osmium tetroxide shows two parallel lines because it labels the polar head groups, which are separated by the hydrophobic interior of the membrane.

Discuss the roles of the genome and proteome in determining cell structure and function.

The genome has a storage function. The genome stores the information to make all of a cell's proteins. The proteome, which is a collection of many different cellular proteins, are the active participants in cell structure and function. Proteins are involved with forming cellular structures, such as the cytoskeleton, and they also play a role in carrying out many cellular functions, such as metabolism, transport, etc. Proteins are also involved in the synthesis other cellular molecules, such as lipids, carbohydrates, and nucleic acids.

an explanation for how a biological process works, that is supported by a large body of evidence and data is called

a theory

what is the name given to the process in which solutes are moved across a membrane against their concentration gradient (low to high)?

active transport

a carrier molecule is required for

active transport and facilitated diffusion

plasma membrane

allows large proteins to enter the cell

a community of organisms interacting with their physical environment is

an ecosystem

imagine that a cell can be treated with a drug that prevents proteins from undergoing large conformational changes. which transport proteins would be unaffected by the drug treatment

aquaporins

a scientist obtains a single celled organism from the bottom of a sulfur hot spring at 260 degrees celsius. when examined under the microscope, it is clear that the cell is very small and contains no nucleus. based on this evidence alone, in what domain of life is this organism?

archaea

Molecules are made up of

atoms

Which is the simplest of all levels of organization?

atoms

the phenomenon through which populations of organisms change over several generations is termed

biological evolution

the following can divide and reproduce like a cell

both mitochondria and chloroplasts

which of the following would not be caused by a motor protein?

breakage of a filament

Mitochondria

burns sugars to make ATP

function of extracellular matrix

cell signaling, organization, support, strength

Cell walls contain

cellulose

all living organisms

consist of one or more cells

what happens when an animal cell is placed into a hypertonic solution

crenation occurs (shriveling)

cellular component responsible for internal support

cytoskeleton

the fluid material located outside of the nucleus that coordinates metabolism is the

cytosol

Following a meal, glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose. This movement is called

diffusion

CO2 can move across a membrane without the aid of a transport protein. this movement is an example of

diffusion and passive transport

Lysosomes contain

digestive enzymes

a pesticide has been found to have a neg effect on diff cell types. in some plants it stops the formation of root nodules and in humans it can stope macrophage from taking up bacteria and generally stops cells from take up protein bound nutrients. the cellular function most likely affected is

endocytosis

the organelle responsible for the biosynthesis of proteins that are destined for secretion by the cell is the

endoplasmic reticulum

insulin is a very large molecule that is too big to pass through transport proteins. following a meal, insulin has to be released by the cells of our pancreas into the blood stream. the release of the protein insulin from pancreatic cells must be occurring by the process of

exocytosis

a researcher tests the hypothesis that drinking orange juice daily helps protect against catching the common cold. what would be the best experimental and control group to test this hypothesis?

experimental: large daily does of orange juice control: large daily glass of placebo orange juice

Golgi bodies (suicide sacs) contains hydrolytic enzymes that can digest worn out cell parts/foreign invaders and play an important role in apoptosis (programmed cell death)

false

a faulty cell membrane is the cause of many diseases such as CF bc of messed up peripheral membrane proteins

false

cellulose in the cell wall is primary energy store for plants

false

genes, which are sections of DNA, are recipes for the cell factory. the cell factory reads these recipes so that it can produce different kinds of carbs

false

liver cells are unique in their structural and functional properties bc early on in development (differentiation) liver cells received strictly liver specific genes. muscle cells are unique in their structural and functional properties bc early on in development (differentiation) muscle cells received strictly muscle specific genes

false

materials move in and out of the nucleus via endocytosis and exocytosis

false

osmosis describes the movement of water from an area of high to low solute concentration

false

the genome has more influence on the function of cells in different organs that does the proteome

false

Endoplasmic Reticulum

functions in internals production of proteins or lipids and transport of macromolecules

Our species is called Homo sapiens. The first word refers to which taxonomical grouping?

genus

which of the following would cause organ transplantation rejection in a person

glycoprotein

which of the following is involved in evolution

happens through the modification of trains in preexisting ancestor, may involve inheritance caused by mutation, gene transfer

When placed in an aqueous solution, amphipathic molecules will orient themselves with

hydrophobic tails in the middle, and hydrophilic head groups facing the water

science is primarily based on

hypothesis testing

Nucleus

makes all types of RNA

Smooth ER

makes and modifies lipids and steroids

a key difference between prokaryotic and eukaryotic cells is that only eukaryotic cells have

membrane bound organelles

cyanide is a poison that damages an organelle involved in making ATP. which organelle must it be

mitochondria

nuclear envelop each of the following is a part of the endomembrane system except

mitochondria

what organelle and function pair can best explain the ability to divide

mitochondria and chloroplasts due to their association with endosymbiosis theory

Golgi apparatus

modifies, labels, sorts, and packages molecules

high permeability in phospholipid bilayer

non polar uncharged molecules

The nucleus is to eukaryotes as the ________ is to prokaryotes.

nucleoid

a kidney in a rat represents which level of organization?

organ

large numbers of ribosomes are present in eukaryotic cells that produce

proteins

you have engineered a new membrane protein in your lab that uses energy to transport a toxic solute out of a cell and against its gradient. this protein is therefore most like a

pump

the route that most accurately describes secretory protein movement through the endomembrane would be

rough er, vesicles, golgi, vesicles, plasma membrane

the gonads produce lipids, such as steroids. the specific steroid-processing organelle in gonad cells is

smooth er

central vacuole

stores water and maintains cellular pressure

in the above experiment, the independent variable is

temp of incubation

the protective layer outside the plasma membrane of the plant cell is called

the cell wall

a researcher decides to test the scientific validity of the common phrase "an apple a day keeps the doctors away". what would be a valid hypothesis to investigate this specific question?

the daily consumption of a single apple does not change the number of visits to the doctor

science is

the inquiry-based effort to describe and explain nature

Solution "A" has a solute concentration of 10% while solution "B" has a solvent concentration of 80%. If they are separated by a selectively permeable membrane

the net direction of water movement will be from solution A to B

"all living organisms are composed of cells" is best related to what kind of scientific statement?

theory

when considering nomenclature for scientific names, what is the difference between the two primates, Homo sapiens, and homo Erectus?

they are animals of different species

which of the following is not a characteristic of channels

they bind their solutes in a hydrophilic pocket, much like an enzyme

the process of polypeptide synthesis is called

translation

which membrane component is most important for allowing large, charged molecules to pass through the membrane?

transmembrane proteins

The capacity to maintain a fairly constant body temperature is a homeostatic process.

true

a 25% salt solution that is placed on fresh water plant cells causes the cells to wilt. the best explanation for this is that water will diffuse by the process of osmosis from the vacuole to the salt water solution

true

cells can sense changes in the environment through alterations in the extracellular matrix

true

in eukaryotes, most proteins contain short stretches of amino acid sequences called sorting signals which direct the protein to the correct cellular location

true

movement of molecules down their concentration gradient can drive the movement of a different molecule against its concentration gradient. this can be seen in secondary active transport

true

one reason why the blob couldn't exist is the surface area to volume ratio

true

the cell is the basic structural/functional unit common to all living organisms

true

the four building blocks of a cell are carbs, proteins, lipids, and nucleic acids

true