QTTA

Question 1

Why are cells so small?

Answer 1

• Cells are small because of their surface area to volume ratio

Question 2

How are Prokaryotes different from Eukaryotes? 5 differences

Answer 2

1 - Euk contain membrane-bound organelles and pro do not
2 - Pro do not have a nucleus; instead they keep their DNA in a cell region called the nucleoid
3 - Pro always unicellular, while Euk are of ten multi-celled organisms
4 - Euk cells are more than 100-10k times larger than Pro cells and are much more complex
5 - The DNA in Euk is stored within the nucleus while DNA is stored in the cytoplasm of prokaryotes

Question 3

What is the CELL THEORY?

Answer 3

• States that all living organisms are made up of cells, which are the basic units of life

Question 4

Why is internal compartmentalization important to Euk cells?

Answer 4

• It vastly improves the efficiency of many cellular functions and prevents potentially dangerous molecules from roaming freely within the cell

Question 5

Examples of how structure suits function for the cell?

Answer 5

• Production of ribosomes in the nucelolus
• ## Exchange of hereditary molecules between the nucleus

Question 6

How is the smooth endoplasmic reticulum different in structure and function compared to the rough endoplasmic reticulum?

Answer 6

• Function - SER responsible for lipid synthesis carbohydrate metabolism, and detoxification, while RER responsible for protein synthesis and processing
• Structure - SER lacks ribosomes on it’s surface whereas RER has ribosomes attached to surface

Question 7

What types of cells would have numerous mitochondria and why?

Answer 7

• Those with high energy demands due to their specialized functions.
• Examples are Heart, Liver, Brain, and Muscle

Question 8

Which cytoskeletal element is made of tubulin dimes?

Answer 8

• Microtubules is made of tubulin dimes

Question 9

Which is made of actin?

Answer 9

• Microfilaments make up actin

Question 10

Which is made of keratin?

Answer 10

• Intermediate filaments make up keratin

Question 11

Which of the 3 proteins discussed is the largest? Smallest? Which is most stable?

Answer 11

• Microtubules are largest
• Microfilaments are smallest
• Intermediate filaments are the most stable

Question 12

What are motor proteins/ where do they get their energy from to move? Give example of a motor protein? How do motor proteins and the cytoskeleton work together to achieve their function?

Answer 12

• A class of proteins that play crucial role in intracellular transport, cellular morality, and other processes
• Myosin’s are an example of a motor protein that move along actin filaments
• They work together by achieving various functions

Question 13

Name 3 types of intercell junctions and their functions. Give examples of the types of cells might have each of these types of junctions?

Answer 13

• Plasmodesmata - Junctions between plant cells that allow the exchange of molecules
• Tight junctions - Junction that seal the gaps between animal cells/prevent leakage
• Gap junctions - Junctions that form channels between animal cells/ allow passage of ions/small molecules

Question 14

Function of each structure/organelle given in this figure (Table 4.2, pg 81)

Answer 14

Plasma Membrane - Regulates what passes into/out of cell; cell to cell recognition; connection and adhesion cell communication

Nucleus - Instructions for protein synthesis/cell reproduction; contains genetic info

Chromosomes - Contain hereditary info used to direct synthesis of proteins

Nucleolus - Synthesis of rRNA/ribosome assembly

Ribosomes - Sites of protein synthesis

ER - Intracellular compartment forms transport vesicles; participates in lipid synthesis/ synthesis of membrane or secreted proteins

Golgi apparatus - Packages proteins for export from cell; forms secretory vesicles

Lysosomes - Digest worn out organelles and cell debris; digest material taken up by endocytosis

Microbodies - Isolate particular chemical activities from rest of cell

Mitochondria - “Power Plants” of the cell, sites of oxidative metabolism

Chloroplasts - Sites of photosynthesis

Cytoskeleton - Structural support; cell movement movement of vesicles within cells

Flagella - Motility or moving fluids over surfaces

Cell wall - Protection; support

Question 15

Where would you find the following, genetic material, gene transcription, production of ribosomes sorting of proteins?

Answer 15

• Genetic Material - Cell’s nucleus
• Gene Transportation - Cell’s Nucleus
• Production of ribosomes - Nucleolus; sorting of prot- various organelles