Mastering Bio Practice For Test

Through which pathway do proteins move out of the cell to the extracellular matrix? smooth ER → lysosome → plasma membrane rough ER → Golgi → plasma membrane Golgi → smooth ER → plasma membrane nucleus → Golgi → plasma membrane

rough ER → Golgi → plasma membrane A secretory protein is produced on a bound ribosome and threaded into the rough ER, where protein folding occurs. The protein is then transported into the Golgi, where it is modified and sorted for delivery through the plasma membrane to the outside of the cell.

Which combinations of single and double covalent bonds result in the appropriate number of bonds around a single carbon atom? 3 single bonds and 1 double bond 3 single bonds 4 single bonds 2 double bonds 2 single bonds and 1 double bond

4 single bonds 2 double bonds 2 single bonds and 1 double bond Single carbon atom forms a total of four bonds.

What is a functional group?

A functional group is a specific configuration of atoms commonly attached to the carbon skeleton of an organic molecule. Functional groups confer specific chemical properties to the molecules of which they are a part. Atoms typically found in functional groups include oxygen, nitrogen, sulfur, and phosphorus.

Which statement about a methyl functional group is correct? A methyl group may be negatively charged. A methyl group is polar. A methyl group consists of a carbon bonded to three hydrogen atoms.

A methyl group consists of a carbon bonded to three hydrogen atoms.

What does a single, double and triple bond look like? What does it mean?

A single bond indicates that two electrons are being shared between two atoms. A double bond indicates that four electrons are being shared between two atoms. A triple bond indicates that six electrons are being shared between two atoms.

The R group on glutamic acid is -CH2CH2COOH, which becomes -CH2CH2COO- at pH=7. Classify glutamic acid based on its R group

Acidic

The slightly electronegative nitrogen atom in this group tends to pick up hydrogen ions from the surrounding solution, and thus this functional group acts as a base. Because of the added hydrogen ion, this group usually has a +1 charge in the cell. This group is characteristic of organic molecules called amines.

Amino Group

The R group on arginine is -(CH2)3NHC(NH2)NH, which becomes -(CH2)3NHC(NH2)N+H2 at pH=7. Classify arginine based on its R group.

Basic

The R group on lysine is -CH2CH2CH2CH2NH2, which becomes -CH2CH2CH2CH2N+H3 at pH=7. Classify lysine based on its R group.

Basic

This group is polar because oxygen has a strong attraction for electrons. If this group is at the end of a carbon skeleton, the molecule is called an aldehyde; otherwise it is called a ketone.

Carbonyl

The two electronegative oxygens of this group pull electrons away from the hydrogen atom. This weakens the bond between oxygen and hydrogen, and the hydrogen atom tends to dissociate from the molecule as a hydrogen (H+) ion. Because it donates hydrogen ions, this group is acidic, and molecules that contain these groups are known as carboxylic acids.

Carboxyl

What is the reason that a modern electron microscope (TEM) can resolve biological images to the subnanometer level, as opposed to the tens of nanometers achievable for the best super-resolution light microscope? Contrast is enhanced by staining with atoms of heavy metal. The focal length of the electron microscope is significantly longer. The electron microscope cannot image whole cells at one time. Electron beams have much shorter wavelengths than visible light. The electron microscope has a much greater ratio of image size to real size

Electorn beams have much shorter wavelengths than visible light

This functional group is polar because the electronegative oxygen has a strong attraction for electrons. Water is attracted to this group, and therefore molecules that have this group (such as sugars) tend to dissolve in water. Alcohols are characterized by this functional group.

Hydroxyl

Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to extend pseudopodia. move vesicles around the cell. perform amoeboid movement. form cleavage furrows. contract muscle fibers.

Move vesicles around the cell

The R group on alanine is -CH3. Classify alanine based on its R group.

Neutal Non Polar

The R group on phenylalanine contains an aromatic ring composed entirely of carbon and hydrogen atoms. Classify phenylalanine based on its R group.

Neutral Non Polar

The R group on proline is composed entirely of hydrogen and carbon atoms. Classify proline based on its R group.

Neutral Non Polar

The R group on tryptophan is a two-ring system composed almost entirely of hydrogen and carbon atoms. Classify tryptophan based on its R group.

Neutral Non Polar

The R group on valine is -CH2(CH3)2. Classify valine based on its R group.

Neutral Non Polar

The R group on asparagine is -CH2CONH2 . Classify asparagine based on its R group.

Neutral Polar

The R group on glutamine is -CH2CH2CONH2. Classify glutamine based on its R group.

Neutral Polar

The R group on threonine is -CH(OH)CH3. Classify threonine based on its R group.

Neutral Polar

The R group on tyrosine is composed of an aromatic ring with an -OH group. Classify tyrosine based on its R group.

Neutral Polar

The R group on methionine is -CH2CH2SCH3. Classify methionine based on its R group.

Neutral non polar

The electronegative oxygens of this functional group draw electrons, and as a result the group acts as an acid, losing hydrogen ions to the surrounding solution. This dissociation leaves the group with a negative charge. This group is important in ATP and the transfer of energy between organic molecules.

Phosphate Group

Molecules termed thiols are characterized by this group, which resembles a hydroxyl group. These groups interact to help stabilize the structure of many proteins.

Sulfhyrdryl Group

Golgi apparatus

The Golgi is composed of a series of flattened membranous discs called cisternae. Each cisterna forms an enclosed space that houses a distinct set of enzymes used to process proteins in a sequential manner as they are prepared for transport to different sites.

Which of the functional groups shown above is most likely to gain a proton and become positively charged? The amino group is most likely to gain a proton. The hydroxyl group is most likely to gain a proton. The carboxyl group is most likely to gain a proton

The amino group is most likely to gain a proton. An amino group acts as a base and can pick up protons from the surrounding medium, becoming positively charged.

Mitochondria

The inner membrane of a mitochondrion has extensive infoldings, which greatly increase the surface area available for key reactions in the energy-producing processes of cellular respiration.

Rough endoplasmic reticulum

This organelle plays an important role in the synthesis of secretory proteins. The outer surfaces of rough ER are studded with ribosomes, the sites where proteins are made. As a protein chain grows from a bound ribosome, it is threaded through a pore in the ER membrane. Once inside, protein folding occurs.

Functional groups confer specific chemical properties to the molecules of which they are a part. In this activity, you will identify which compounds exhibit certain chemical properties as well as examples of those six different compounds.

alcohol: is highly polar andmay act as a weak acid (OH) carboxylic acid: acts as an acid (COOH) aldehyde: may be a structural isomer of a ketone (C=O) thiol: forms disulfide bonds (S-H) amine: acts as a base (NH2) organic phosphate: contributes negative charge (PO4)