L4: Introduction To Human Cells

Question 1

What are the 2 classification of cells?

Answer 1

• Prokaryotes
• Eukaryotes

Question 2

What are prokaryotes?

Answer 2

• single celled organisms without a nucleus
  E.g/ eubacteria, arachaebacteria, cyanobacteria

Question 3

What are eukaryotes?

Answer 3

• Single or multicellular organisms with a membrane bound nucleus
  E.g/ plant and animal cells

Question 4

What is the variety of human cells like?

Answer 4

• all cells have same genetic code
• all cells have similar internal strcutures but vastly different functions

Question 5

What does pluripotent mean?

Answer 5

The cell can differentiate into many different cells

Question 6

Give examples for cells that pluripotent stem cells can differentiate into

Answer 6

• pancreatic islet cells
• heart muscle
• blood cells
• nerve cells
• bone marrow cells

Question 7

What component can the cell structure be separated into?

Answer 7

• nucleus
• cytoplasm (cytosol, inclusions, organelles, protein fibres)
• cell membrane

Question 8

Examples of inclusions

Answer 8

• lipids
• glycogen
• ribosomes

Question 9

Examples of organelles

Answer 9

• endoplasmic reticulum (smooth and rough)
• golgi apparatus
• mitochondria
• lysosomes
• peroxisomes

Question 10

Examples of protein fibres

Answer 10

• cytoskeleton
• centrioles
• cilia
• flagella

Question 11

Order of microscopic observation of cells (biggest to smallest)

Answer 11

• typical human cells
• mitochondrion
• lysosome
• robosome
• plasma membrane
• protein molecule
• hydrogen atom

Question 12

What’s the difference in cytoplasm and cytosol?

Answer 12

Cytoplasm: everything in the cell except the nucleus
Cytosol: also excludes other organelles

Question 13

What are the different classes of biological molecules?

Answer 13

• nucleic acids (DNA, RNA, Nucleotides)
• protein (a/a, polypeptides)
• lipids (FA, triglycerides, steroids)
• carbohydrates (mono/di/polysaccharides)

Question 14

What is central dogma of cell biology?

Answer 14

The process by which the instructions in DNA are converted into a fuctional product

Question 15

What is the function of the nucleus? + extra info

Answer 15

• storage and transmission of genetic info to the next gen of cells
• DNA is wound up around histones = chromatin
• Chromosomes are chromatin threads condensed

Question 16

What are some of the nuclear structures?

Answer 16

• nuclear envelope
• nucleolus
• nuclear pores
• chromatin
  (+ nucleoplasm)

Question 17

Features of the nuclear envelope

Answer 17

• composed of 2 membranes
• openings called nuclear pores
  = mRNA transcribed from DNA moves out through them
  = proteins that modulate gene expression in DNA move in through them

Question 18

What are the types of endosplasmic reticulum?

Answer 18

• Rough ER
• Smooth ER

Question 19

What is the RER?

Answer 19

• double membrane with ribosomes bound to it
• involved in translation, packaging protein to send to the GA

Question 20

What is the SER?

Answer 20

• site where certain lipid molecules are synthesized
• plays role in detoxification of certain hydrophobic
• stores and releases calcium ions

Question 21

What are ribosomes?

Answer 21

• the site of protein synthesis
  (From a/a using genetic info from mRNA

Protein are synthesised
- on free ribosomes and released into the cytosol
- ribosomes on the RER

Question 22

What is the golgi apparatus?

Answer 22

• series of closely apposed, flattenes membranous sacs
• proteins pass, get modified, sorted and travel to various cell locations

Question 23

What are secretory vesicles?

Answer 23

Vesicles containing proteins secreted from the GA

Question 24

What is the mitochondria?

Answer 24

• organelle that participates in chem processes that transfer energy from chem bonds of nutrient molecules to ATP molecules
• most of the energy used by the cells is from ATP by aerobic respiration

Question 25

What are lysosomes?

Answer 25

• spherical organelles surrounded by single membrane
• fluid within is acidic and contains digestive enzymes
• digesting food, organelles, cells

Question 26

What are peroxisomes?

Answer 26

• dense oval bodies enclosed by a single membrane
• soncumes molecular O, removes H from lipids, alcohol, and potentially toxic ingested substances

Question 27

What are endosomes/vesicles?

Answer 27

• vesicles pinch off the plasma membrane travel to and fuse to endosomes
• endosomes can pinch vesicles off that return to the plasma membrane
• endosomes are involved in sorting. Modifying and diecting vesicular traffic

Question 28

What are types of cytoskeletons?

Answer 28

• actin filament (7nm, G-actin)
• intermediate filament (10nm, several proteins)
  = microtubule (25nm, tubulin)

Question 29

What is cilia?

Answer 29

Slender protuberances that project from the much larger cell body

Question 30

What is flagella?

Answer 30

Lash-like appendage that protrudes from the cell body