Kafli 3 - Æfingar í lok kafla

Æfingar í lok kafla

Fjölvalsspurningar

3.1 Myndun Lífrænna Stórsameinda

Dehydration synthesis leads to formation of

monomers
polymers
water and polymers
none of the above

During the breakdown of polymers, which of the following reactions takes place?

hydrolysis
dehydration
condensation
covalent bond

The following chemical reactants produce the ester ethyl ethanoate (C₄H₈O₂):

C₂H₆O + CH₃COOH

What type of reaction occurs to make ethyl ethanoate?

condensation
hydrolysis
combustion
acid-base reaction

3.2 Kolvetni

An example of a monosaccharide is ________.

fructose
glucose
galactose
all of the above

Cellulose and starch are examples of:

monosaccharides
disaccharides
lipids
polysaccharides

Plant cell walls contain which of the following in abundance?

starch
cellulose
glycogen
lactose

Lactose is a disaccharide formed by the formation of a ________ bond between glucose and ________.

glycosidic; lactose
glycosidic; galactose
hydrogen; sucrose
hydrogen; fructose

Which of the following is not an extracellular matrix role of carbohydrates?

protect an insect’s internal organs from external trauma
prevent plant cells from lysing after the plant is watered
maintain the shape of a fungal spore
provide energy for muscle movement

3.3 Lípíð

Saturated fats have all of the following characteristics except:

they are solid at room temperature
they have single bonds within the carbon chain
they are usually obtained from animal sources
they tend to dissolve in water easily

Phospholipids are important components of ________.

the plasma membrane of cells
the ring structure of steroids
the waxy covering on leaves
the double bond in hydrocarbon chains

Cholesterol is an integral part of plasma membranes. Based on its structure, where is it found in the membrane?

on the extracellular surface
embedded with the phospholipid heads
within the tail bilayer
attached to the intracellular surface

3.4 Prótein

The monomers that make up proteins are called ________.

nucleotides
disaccharides
amino acids
chaperones

The α-helix and the β-pleated sheet are part of which protein structure?

primary
secondary
tertiary
quaternary

Mad cow disease is an infectious disease where one misfolded protein causes all other copies of the protein to begin misfolding. This is an example of a disease impacting ____ structure.

primary
secondary
tertiary
quaternary

3.5 Kjarnsýrur

A nucleotide of DNA may contain ________.

ribose, uracil, and a phosphate group
deoxyribose, uracil, and a phosphate group
deoxyribose, thymine, and a phosphate group
ribose, thymine, and a phosphate group

The building blocks of nucleic acids are ________.

sugars
nitrogenous bases
peptides
nucleotides

How does the double helix structure of DNA support its role in encoding the genome?

The sugar-phosphate backbone provides a template for DNA replication.
tRNA pairing with the template strand creates proteins encoded by the genome.
Complementary base pairing creates a very stable structure.
Complementary base pairing allows for easy editing of both strands of DNA.

Gagnrýnin hugsun

3.1 Myndun Lífrænna Stórsameinda

Why are biological macromolecules considered organic?

What role do electrons play in dehydration synthesis and hydrolysis?

Amino acids have the generic structure seen below, where R represents different carbon-based side chains.

The generic structure of amino acids is shown. A nitrogen atom is single bonded to two hydrogen atoms and one carbon atoms. The carbon atom is single bonded to one hydrogen atom, one R atom, and one carbon atom. R represents different carbon-based side chains. The carbon atom is double bonded to one oxygen atom and single bonded to a hydroxide atom.

Describe how the structure of amino acids allows them to be linked into long peptide chains to form proteins.

3.2 Kolvetni

Describe the similarities and differences between glycogen and starch.

Why is it impossible for humans to digest food that contains cellulose?

Draw the ketose and aldose forms of a monosaccharide with the chemical formula C₃H₆O₃. How is the structure of the monosaccharide changed from one form to the other in the human body?

3.3 Lípíð

Explain at least three functions that lipids serve in plants and/or animals.

Why have trans fats been banned from some restaurants? How are they created?

Why are fatty acids better than glycogen for storing large amounts of chemical energy?

Part of cortisol’s role in the body involves passing through the plasma membrane to initiate signaling inside a cell. Describe how the structures of cortisol and the plasma membrane allow this to occur.

3.4 Prótein

Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.

Describe the differences in the four protein structures.

Aquaporins are proteins embedded in the plasma membrane that allow water molecules to move between the extracellular matrix and the intracellular space. Based on its function and location, describe the key features of the protein’s shape and the chemical characteristics of its amino acids.

3.5 Kjarnsýrur

What are the structural differences between RNA and DNA?

What are the four types of RNA and how do they function?

Sjónrænar æfingar

3.2 Kolvetni

Mynd 3.5 What kind of sugars are these, aldose or ketose?

3.4 Prótein

Mynd 3.23 Which categories of amino acid would you expect to find on the surface of a soluble protein, and which would you expect to find in the interior? What distribution of amino acids would you expect to find in a protein embedded in a lipid bilayer?

3.5 Kjarnsýrur

Mynd 3.33 A mutation occurs, and cytosine is replaced with adenine. What impact do you think this will have on the DNA structure?