PoBio Exam 2

chapter questions, learning outcomes, important lecture notes

according to cell theory

new cells arise only from

proteins are processed and modified in the interior of the

rough endoplasmic reticulum

which cellular structure is responsible for packaging materials with the cell

golgi apparatus

In order to digest materials within a cell, the material to be digested must fuse with

a lysosome

This organelle absorbs and converts oxygen while releasing CO2 and water

mitochondria

cellular respiration is best associated with the

mitochondria

Which of the following is NOT evidence supporting the endosymbiotic theory

A. the vacuoles can "come and go" across the plasma membrane.

B. mitochondria and chloroplasts have their own DNA.

C. mitochondria and chloroplasts are nearly identical to some free-living prokaryotes.

D. mitochondria and chloroplasts divide by splitting.

A.

Choose all that are correct. The nucleus…

A. is found in eukaryotes.

B. has a single-layered membrane.

C. stores genetic material.

D. is the only organelle containing DNA.

E. contains chromatin.

F. can live independently of a cell.

A. C. E.

Choose all that are correct. The nucleus…

A. is found in bacteria.

B. has a double membrane.

C. stores genetic material.

D. is the only organelle containing DNA.

E. contains chromatin.

F. can live independently of a cell.

B. C. E.

What structures have hereditary material inside of it

mitochondrion, nucleus, and chloroplast

What would be found as parts of all cells

DNA, plasma membrane, ribosomes

A flagellum is able to bend due to being made of ______________ that can bend by sliding past one another under the influence of the motor protein _____________.

microtubules, dynein

The innemost membrane of the chloroplast is referred to as the

thylakoid membrane

Imagine starting in the innermost space of the chloroplast and moving outward until leaving the chloroplast and entering the cytoplasm. What is the starting points an proper order of things you would move through?

thylakoid space - thylakoid membrane - stroma - inner membrane - outer membrane

True or false. the cell membrane serves as a site for protein synthesis

False

according to the fluid-mosaic model of membrane structure

proteins float inside or within the phospholipid bilayer

The plasma membrane is composed of

phospholipids and proteins

proteins do NOT pass through cell membranes becuase

they are very large molecules

permeability refers to

the extent to which a membrane allows a substance to pass through

if you have 10% sugar solution and a 35% sugar solution, how does the 10% solution

hypotonic

the term hypertonic menas

a higher solute concentratio

an isootonic solution means that the solut concentaion outside the cell

is the same as inside the cell

True or false. facilitated transport by carrier proteins is represented by the glucose carrier ta can be hundreds of molecules a second

True

carrier molecules are required for…

both facilitated diffusion and active transport

when a substance moves from an area of low concentration to an area of high concentration while using energy, the process is termed

active transport

If a cell lacks ATP, which of the following processes would cease to operate immediately

sodium/potassium pump

when an intestinal cell ingests substances inside very small vesicles that can only be seen with an electron microscope, this is

pinocytosis

Receptor-mediated endocytosis involves all of the following EXCEPT

A. receptor proteins to bind to specific molecules.

B. a coated pit due to a layer of fibrous protein on the cytoplasmic side of the membrane.

C. the mechanism for regulating exchange between a mother and fetus.

D. secretion of materials from a cell.

D

Which of the following refers to materials only leaving the cell?

exocytosis

What condition must be met for diffusion to occur

a concentration difference

Glucose levels go up in the bloodstream after a meal. Beta cells of the pancreas detect the elevated glucose levels. This causes them to secrete insulin protein into the bloodstream. How is this secretion accomplished?

Motor proteins drag insulin-containing vesicles to the cell membrane along microtubules

The GLUT protein moves glucose across a membrane by

facilitated diffusion

What statement most accurately describes the second law of thermodynamics?

 Energy cannot be changed from one form to another without a loss of usable energy.

What statement most accurately describes the first law of thermodynamics?

Energy can be neither created nor destroyed but it can be changed from one form to another

True or False. Carbon dioxide and water forming glucose without the input of energy is a correct statement about the second law of thermodynamics and entropy

False

The high energy bond in ATP that is used by the cells is found in or between

the phosphate group

what contains an adenine base, a ribose sugar, and three phosphate groups

ATP

The main reason that ATP is considered the energy currency in cells is because it

contains accessible energy in phosphate bonds

during an enzymatic reaction, what happens to the enzyme

the enzyme and the substrate form a temporary complex

Enzymes are specific. this means that they

have a particular substrate

Which of the following statements is true about enzymes?

A. Their 3D shape can vary and still be active.

B. Boiling temperatures do not affect their activity.

C. They catalyze only one specific type of reaction.

D. They can associate with a wide variety of substrates.

E. They are unaffected by changes in pH.

C

Adding the correct enzyme can ___ the energy of activation

lower

Each enzyme has a particular substrate because enzymes

have active sites complementary in shape to their substrates

The function of an enzyme is to

increase the rate of a metabolic reaction

in feedback inhibition of a metabolic pathway, where does the inhibitor bind

to the enzyme of the first reaction

The location in which the enzyme and substrate complexes is called the

active site

Which molecules are the reactants or substrates for aerobic respiration

oxygen and glucose

Which molecules are the products of aerobic respiration

carbon dioxide and water

what is a substrate of cellular respiration

glucose

Which of the following does not describe the role of NAD+ in cellular respiration?

A. It accepts two electrons.

B. It is a coenzyme.

C. It is necessary for glycolysis.

D. It is broken down to CO2 and water.

D.

What role does NAD+ play in cellular respiration

It’s a coenzyme

What are the input requirements of glycolysis

ATP, NAD+, glucose, ADP

The final products of glycolysis are…

pyruvate, ATP, NADH + H+

Where does glycolysis take place within the cell

cytoplasm

Muscles undergo fermentation when…

no oxygen is available

Why do organisms without oxygen need to convert pyruvate to lactate

in order to regenerate NAD+

What phase(s) of cellular respiration produces NADH

glycolysis, preparatory reaction, and citric acid cycle

Which stages will produce carbon dioxide in cellular respiration

preparatory reaction, citric acid cycle

The largest number of ATP molecules is produced in which phase of cellular respiration

electron transport chain

Pyruvate is converted to a two-carbon acetyl group attached to coenzyme A (CoA), and CO2 is given off. This phase is called

preparatory reaction

Which pathway in cellular respiration will produce ATP, NADH, and carbon dioxide?

citric acid cycle

The production of ATP as a result of an electrochemical gradient is called

chemiosmosis

Why does chemiosmosis require a membrane

to separate two compartments of the cell to allow for gradient formation

What is the final electron acceptor at the end of the electron transport chain in respiration

oxygen

Which molecules donate electrons to the electron transport chain of respiration

NADH, FAD

Where is NAD+ converted to NADH

cytoplasm and matrix of the mitochondrion

ATP and ADP have a strong negative charge. How could that get into and out of the mitochondrion

through a membrane transport protein

What are the products of photosynthesis

oxygen, carbohydrate

The raw materials or reactants of the photosynthetic process include…

carbon dioxide and water

at the cellular level, photosynthesis occurs within

the chloroplast

solar energy is captured by…

pigments

why are plant leaves green

They reflect green wavelengths of light

The metabolic events that move electrons from water to NADP+ are referred to as what

a noncyclic electron pathway

Water is split and oxygen is released in…

the noncyclic electron pathway

What are the stages of the Calvin cycle

carbon dioxide fixation, carbon dioxide reduction, and regeneration of RuBP

One of the products of the Calvin cycle is…

G3P

The Calvin cycle reactions are dependent upon a supply of

carbon dioxide, NADPH, ATP

What are the two sets of reactions for photosynthesis

light reactions, Calvin cycle reactions

The substance that initially traps solar energy in photosynthesis is…

chlorophyll

The light reactions could be viewed as analogous to a hydro-electric dam. In that case, the wall of the dam that holds back the water would be analogous to…

A thylakoid membrane

The light reactions could be viewed as analogous to a hydro-electric dam. In that case, the water stored in the reservoir above the dam would be analogous to…

hydrogen ions (protons)

Imagine starting in the innermost space of the chloroplast and moving outward until leaving the chloroplast and entering the cytoplasm. What is the starting points an proper order of things you would move through?

thylakoid space - thylakoid membrane - stroma - inner membrane - outer membrane

The inner most membrane of the chloroplast is referred to as the

thylakoid membrane

What is the name of the enzyme that fixes carbon dioxide during photosynthesis

RuBP Carboxylase

True or False. Chloroplasts are green because chlorophyll absorbs green light

False

List the principles of the cell theory

all living organisms are composed of one or more cells

a cell is the basic structural and functional unit of living organisms

all cells arise from pre-existing cells

2 types of light microscopes and the use of each

stereomicroscope- looks at the surface of a sample

compound microscope- looks at thin cross-sections of a sample

2 types of electron microscopes and the use of each

SEM- creates an image by detecting reflected electrons

TEM- uses transmitted electrons (electrons that pass through a sample) to create an image

How do magnification, contrast, and resolution relate to microscopy

magnification- make small objects seem larger

contrast- darkness of background relative to the specimen

resolution- distinguish two objects from each other

name the parts of the plasma membrane

lipids (phospholipids and cholesterol), proteins, and carbohydrate groups

what is the function of plasma membrane

provides protection for a cell and transports things in and out of the cell

explain the general differences of bacteria, archaean, and eukaryotic cells

archaea and bacterial cells lack organelles

Explain the roles of different cytoskeletal elements in cells

gives cell its shape and helps organize the cell’s parts

Describe the origin of mitochondria and chloroplasts in cells.

evolved from engulfed prokaryotes that once lived as independent organism

Describe the fluid mosaic model of membrane structure.

mosaic of phospholipids, cholesterol, proteins, and carbohydrates- gives the membrane a fluid character

Describe signal transduction

the transmission of molecular signals from a cell’s exterior to its interior

5 functions of membrane proteins

intercellular transport, motility, anchoring cells to their environment, cell to cell recognition, carrying out enzymatic reactions

Explain the relationship between membrane structure and selective permeability.

because of the tightly packed hydrophobic tails, large molecules are prevented from diffusing through

diabetes mellitus

glucose stays in your blood and doesn’t reach your cells because of a lack or poor use of insulin

Describe how insulin is released into the blood

insulin is released from the beta cells in your pancreas in response to rising glucose in your bloodstream