bio lesson 3

Rough Endoplasmic Reticulum

An endomembrane system covered with ribosomes where many secretory proteins for transport are assembled.

smooth endoplasmic reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated/stored, and toxic substances are broken down.

Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?

Keep the cough drop whole. This maintains the smallest surface-to-volume ratio and slows the dissolution of the cough drop.

Lysosomes contain digestive enzymes. Perioxosomes contain H2O2. Both the digestive enzymes and H2O2 can kill cells. How is it possible that cells can contain toxic substances without being damaged?

Membranes isolate substances into separate compartments. The contents of each membrane-bound organelle are isolated from other the contents of other organelles.

Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?

Mitochondrion. use o2 and release co2 to form ATP

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?

Prokaryotic cells lack any internal membranous compartmentalization whereas eukaryotic cells have membrane-bound organelles.

Cytosol

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.

Which of the following is a function of the rough endoplasmic reticulum?

These proteins are made by the rough endoplasmic reticulum and then processed by the Golgi apparatus before being inserted into the cell membrane

cells that make a lot of proteins have

a lot of ribosomes

cytoskeleton act like

a skeleton in providing for structural support as well as movement

chromosomes

all cells have one or more, carry genes made of DNA

The membranous compartmentalization of a cell

allows different chemical conditions to be maintained in different parts of the cell.

Mitochondria are found in _____.

both plant cells and animal cells

mitochondria are organelles that carry out

cellular respiration in all eukaryotic cells

animal cells contain

centrosome which is the region where microtubules grow from , contains a pair of centrioles

Which choice has its items arranged in descending order of size (i.e., from largest to smallest)?

chicken egg, Paramecium, animal cell, mitochondrion, viruses, lipids

Which of the following lists includes only components that provide structural support, allow movement, or enable communication between cells? Keep in mind that this is a functional, not purely structural, classification.

cytoskeleton, plant cell wall, plasma membrane

Where would ribosomes be located that are responsible for producing enzymes which play a role in sugar metabolism?

cytosol, free ribosomes function as enzymes that catalyze the initial steps of sugar metabolism

ribosomes bound to endoplasmic reticulum generally make proteins

destined either for inclusion into membranes; for packaging within certain organelles, such as lysosomes; or for export from the cell.

intermediate filaments

found in the cells of most animals, fibrous proteins that supercoil into cables, reinforces cell shapes and protect organelles, permanent fixtures in cell

Ions flow through _______ between cells of heart muscle. How does this help the heart do its job?

gap junctions: coordinate contraction

The transport process for golgi apparatus

intercepts ER vesicles, modifies the contents for export, and repackages the material in a Golgi vesicle that can fuse with the plasma membrane.

The plant cell wall

is a protective structure made of cellulose fibrils.

The maximum size of a cell is limited by _____.

its need for enough surface area to make exchanges with its environment

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome

Which of the following organelles breaks down worn-out organelles?

lysosomes

Tay-Sachs disease disease results from the malfunction of

lysosomes, a lipid-digesting enzyme missing, causes an accumulation of lipids in brain cells.

in animal cells but not plant cells

lysosomes, centrosomes with centrioles, flagella

endomembrane system includes

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles and the plasma membrane.

prokaryotic cells have a region that DNA is coiled into called

nucleoid

phospholipids group together to form

phospholipid bilayer

Which of the following functions is performed by the Golgi apparatus?

processing proteins for secretion and for use within the cell

The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The pigment melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function.Melanocytes use many enzymes to produce melanin. Based on their function, you would expect melanocytes in the skin to have a higher than usual number of

ribosomes

cell wall of prokaryotes

rigid structure outside the plasma membrane, protect cell and maintain shape

golgi appartus function

stores, modifies, and packages proteins.

Mictrotubules

straight hollow tubes composed of globular proteins called tubulins

free and bound ribosomes are

sturcturally identical and can work in either location depending on the type of protein

Why can't cells get very big?

the maximum size needs to have a surface area large enough to service the volume of a cell

According to the endosymbiont theory, the benefit that was gained when the ancestor of the eukaryotic cell incorporated a photosynthetic prokaryote was that

the newcomer provided nourishment to its host

To enter or leave any cell, substances must pass through _____.

the plasma membrane

Mitochondria appear in the greatest numbers in cells that are _____.

metabolically active

The genetic center of the eukaryotic cell is the __________.

nucleus

All of the following originate from the endomembrane system EXCEPT _______.

perioxisomes

You would expect a cell with an extensive Golgi apparatus to _____.

secrete a lot of material

What comes to mind when you hear the term "9 + 2"?

"9 + 2" refers to the structural arrangement of microtubules in both cilia and flagella. The arrangement consists of a central pair of microtubules ("2") surrounded by nine pairs of microtubules ("9").

Microfilaments

(actin filaments) support the cell's shape and are involved in motility. form a 3d shape inside plasma membrane that support cell shape/cell movement

Which of the following statements about cellular metabolism is true

- Cellular metabolism often occurs on the surfaces of internal membranes. - Cellular metabolism can occur within organelles. - Cellular metabolism includes different processes that require different conditions.

The light microscope can magnify specimens by at most ______ times and can resolve details down to about the size of _______.

1,000: 0.2 µm

4 basic functional groups of eukaryotic cells

1. nucleus and ribosomes carry out the genetic control of the cell 2. Organelles involved in the manufacture, distribution, and breakdown of molecules are: ER, golgi , lysosomes, vacuoles, peroxisomes 3. Mitochondria in all cells and chloroplasts in plant cell function in energy processing 4. structural support, movement, communication, between cells involve cytoskeleton, plasma membrane, plant cell wall

central vacuole

A membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development.

_____ are found only in plant cells, but _____ are found in both plant and animal cells.

Central vacuoles; ribosomes

nucleus

Control center of the cell. Contains DNA.controlls cells activities by directing protein synthesis

What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?

Each of these organelles is a member of the endomembrane system and is constructed of the same type of membrane.

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

Jonah has consumed too much alcohol on a regular basis for many years. While celebrating his graduation from skydiving school, he cut his foot on a broken beer bottle and developed an infection. Over the next two weeks, several antibiotics proved ineffective and his infection grew worse. Why might this have happened?

Jonah's high levels of detoxifying enzymes made the antibiotics less effective.

Which of the following statements about the cytoskeleton is false?

Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.

Which of the following organelles is present in a prokaryotic cell, but not a eukaryotic cell?

Prokaryotic cells have a region called the nucleoid that contains coiled DNA. No membrane surrounds the nucleoid.

Which of the following is a function of the central vacuole?

Storing compounds produced by the cell

Which of the following describes the function of the chloroplast?

The chloroplast converts light energy to chemical energy. PHOTOSYNTHESIS

Which of the following statements regarding the endomembrane system is false?

The endomembrane system is a system of interrelated membranes that are all physically connected. no bc some can be connected and others are linked by vesicles

What is the relationship between the Golgi apparatus and the plasma membrane?

The finished products of the Golgi apparatus may leave the cell through vesicles that fuse with the plasma membrane.

plasma membrane

The membrane at the boundary of every cell that acts as a selective barrier for the cells from surroundings, thereby regulating the cell's chemical composition.

transport vesicles

Vesicles in transit from one part of the cell to another.

Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?

Vesicles travel along microtubules as they move from one part of the cell to another.

Perioxomes

an organelle found in most eukaryotic cells that contains enzymes for oxidizing fatty acids and other compounds for cellular work, including many toxins, rendering them harmless

Vacuole

an organelle that stores food, water, and other materials needed by the cell

ribosomes uses instructions from nucleus, written in mRNA, to

build proteins

What effect do inherited lysosomal storage diseases have on cells?

buildup of undigested material because key lysosomal enzymes are absent

Lysosomes

cell organelle filled with digestive enzymes needed to break down certain materials in the cell

plant cell has but animal cell does not

cell wall, central vacuole, plasmodesma

prokaryote cells have

cell wall, plasma membrane, no nucleus/membrane bound organelles

plant cells do not contain

centrioles/centrosome

DNA from nucleus is assembled into

chromosomes

flattened ER sacks are ----, golgi sacs are not

connected

The function of the chloroplast is to _____

convert light energy to chemical energy of a glucose molecule.

All other forms of life other than bacteria and archaea are

eukaryotes

After leaving the ER, many transport vesicles travel to?

golgi apparatus

Nucleolus

in nucleus, ribosomal RNA is made according to instructions from DNA

Where do the chemical reactions of cellular respiration take place in plants?

in the matrix of the mitochondrion. located within the inner membrane of the organelle. This is the case for all eukaryotic cells. The enzymes required for creating ATP are embedded in the highly-folded cristae within the matrix.

Protein synthesis requires the use of mRNA, which

is translated by the ribosomes into the amino acid sequences of proteins.

lysosomes are like a recycling center because

it breaks down damaged molecules and recycles their molecules

Because volume increases at a faster rate than surface area, large cells have proportionately

less plasma membrane surface area.

A differential interferencecontrast microscope uses __________ to examine a specimen. Which type of microscope would one use to examine the internal structure of a nucleolus?

light: transmission electron microscope

Which of the following are present in animal cells but not in plant cells?

lysosome and centrosomes

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA, ribosomes work to make mRNA translated into amino acid sequence

The protein actin is a component of a(n) __________.

microfilament

Which of the following lists the smallest of the cell's cytoskeletal elements, and what is the function of these elements?

microfilaments interact with a protein called myosin within muscle cells to produce muscle contraction.

The internal skeleton of a cell is composed of _____

microtubules, intermediate filaments, microfilaments

three fibers of cytoskeleton

microtubules, microfilaments, intermediate filaments

Where in a cell is ATP made?

mitochondria

the golgi apparatus acts as a

molecular warehouse and processing station for products manufactured by ER

microtubules can help move

motor proteins and chromosomes when cell divide. mictrotubules are the main componets of cilia and flagella

Each phospholipid is composed of two distinct regions:

negatively charged phosphate group and two nonpolar fatty acids

Phospholipid tails are

non-polar (hydrophobic)

Ribosomal RNA is produced in the ________ according to instructions from the cell's _________. Subunits are then formed from ribosomal RNA and ______ imported from the cytoplasm.

nucleolus: DNA: proteins

eukaryotic cells have

nucleus and membrane bound organelles

Chloroplasts are found in __________.

plant cells and some protists

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane

Phospholipid heads are

polar, hydrophilic

Consider a free ribosome. What enters this organelle, and what comes out of it, in the process of protein synthesis?

polypeptide comes out of a free ribosome. mRNA is a sequence of nucleotides dictated by the cell's DNA. After entry, the nucleotide sequence is translated into a sequence of amino acids by the ribosomal machinery.

The cell wall of plants consists of which of the following substances?

polysaccharides and proteins

Bacteria and Archaea are

prokaryotes

Both prokaryotic and eukaryotic cells do have

ribosomes

Much of the intracellular structure of a eukaryote cell is involved in protein synthesis. The accompanying figure shows the amounts of protein in cells at different parts of the cell cycle between two cell divisions. G1 is a stage just after the cell has divided, and G2 is the stage just before the cell divides again. S is a stage when the cell is synthesizing material such as DNA, mitochondria, and other organelles. The protein measured in the cells was likely synthesized by

ribosomes

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

ribosomes

The endomembrane system is in a constant state of renewal. Which organelle manufactures new membrane for this system?

rough ER

Which of the following organelles is responsible for folding proteins and adding the short sugar chains that make them glycoproteins?

rough ER

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER)

The plasma membrane would fit into which general function category?

support, movement, communication

Membrane proteins are synthesized by ribosomes that are attached to __________.

the ER

Which of the following is (are) the hydrophilic regions of the cell membrane?

the regions nearest to the external and internal environments. The regions farthest from the external and internal environments are hydrophobic

The function of the nucleolus is

to manufacture ribosomal RNA.

Which of the following can perform these functions in plants: digestion, water circulation, pigmentation, and food storage?

vacuole

As cell size increases, the

volume increases proportionally more than the surface area.