Cell+Molecular Biology Paper 1

December 2021

What pair of characteristics are correct for the cellular processes of exocytosis and endocytosis?

Exocytosis is the secretion of cellular materials and endocytosis is when vesicles are moved away from the plasma membrane

What could be a function of a membrane protein?

Enzymatic activity

Which sequence shows increasing relative size?

Membrane thickness, virus, bacterium

The diagram shows a model of a biological membrane. What do labels I (string outside), II (half bagel inside) and III (ball in the corner) illustrate?

I \= Glycoprotein
II \= Integral protein
III \= Hydrophilic phosphate head

What describes the functions of the Golgi apparatus and the Rough endoplasmatic reticulum

Golgi apparatus \= Processing of proteins
RER \= Synthesis of proteins for cell secretion

A student observes and draws an Amoeba, using the high power lens of a microscope. The diameter of the drawing is 100 mm. The actual diameter of the Amoeba is 100 µm. What is the magnification of the drawing?

1000

What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells have no internal membrane compartments while eukaryotic cells have internal membrane compartments

What is osmosis?

The movement of water through a membrane from a low to a high solute concentration.

In the structure of DNA, what binds with cytosine?

Deoxyribose

Molecules A and B are amino acids and C is a dipeptide. Which reaction represents a condensation reaction?

A + B --\> C + H20

What are these molecules? (C with three Hs to the left with a C double O binding and OH group to the right. Pentagram structure with one HOH2C group)

Fatty acid (tail) and ribose (glucose would be CH2 not HOH)

The following shows a micrograph. In what order do the events of mitosis occur?

2 (no real formation), 1 (spider in the middle), 3 (spider to the sides) and 4 (two clumps to each side)

Why does exposure to high temperatures cause an enzyme to lose its biological properties?

The three dimensional structure of the enzyme becomes changed (denaturation)

How would the following DNA sequence, ACGTTGCATGGCA, be transcribed?

UGCAACGUACCGU

What causes water to have a relatively high boiling point?

Hydrogen bonds between water molecules

Which compound is inorganic?

C. H-N-H-H. (Includes an N)

A certain gene in a bacterium codes for a polypeptide that is 120 amino acids long. How many nucleotides are needed in the mRNA to code for this polypeptide?

360 (x3, three bases per amino acid)

What is "naked DNA"?

DNA not associated with proteins

During the process of replication, which bond(s) in the diagram of DNA below is/are broken?

4 and 5 (the hydrogen bonds between the bases in the middle)

Which molecules are formed as a direct result of translation and transcription?

Proteins are a direct result of translation and mRNA is a direct result of transcription

What is the function of proteins in passive transport?

To serve as channels so that specific molecules diffuse across the membrane.

Where is an anti-codon located?

tRNA (not ribosomes)

How is the sequence pf DNA conserved?

Complementary base pair matching during the DNA replication

Which of the above chemical structures represent fatty acids and carbohydrates?

Fatty acids is I only (HO and double O at the end) and carbohydrates was III and IV (six edges)

Enzyme activity has been measured for two enzymes at different pH values. At which pH is one enzyme optimal and the other enzyme denatured?

pH \= 8 (at the second one's peak while the other had flattened)

Which functions of life are carried out by all unicellular organisms?

Response, homeostasis, metabolism and growth (MR H GREN \= Metabolism, Response, Homeostasis, Growth, Reproduction, Excretion, Nutrition)

The cell theory states that cells come from pre-existing cells. What biological process allows this to occur?

Cytokinesis

Which structures have a phospholipid bilayer?

Vesicle and nucleus (not nucleoid)

What can be found in plant cells but not animal cells?

Starch

Why do multicellular organisms have emergent properties?

They show properties that can only result from the interaction of many cells.