Structure of Eukaryotic Cell

Question 1

What are the 7 key principles that make up Cell Theory of Biology?

Answer 1

1. All living things are made up of cells
2. Cells are the smallest unit of life
3. Cells come from other cells
4. The activity of the organism depends on the total activity of independent cells
5. Energy flow occurs within all cells
6. Cells contain DNA
7. Cells are basically the same in chemical composition in organsims of similar species

Question 2

All life forms are made from cells. What are the “biological building blocks of life” from smallest to largest?

Answer 2

Unicellular
Multicellular
- Cells eg muscle cell
- Tissues eg cardiac muscle
- Organs eg heart
- Organ system eg circulatory system
- Organism eg mammal

Question 3

Cells arise from pre-existing cells. What are some of the ways this can occur?

Answer 3

Mitosis = parent cell divides into two identical daughter cells)

Meiosis = reduces number of chromosomes in the parent cell by half to produce 4 gamete cells

Binary fission = asexual reproduction by a separation of the body into two new bodies

Question 4

What are the universal features of cells?

Answer 4

Plasma membrane
Genome
Information transfer
Energy utilisation
Cytoplasm

Question 5

What is the plasma membrane?

Answer 5

• Selective barrier to segregate the cell form the environment
• Made up of a phospholipid bilayer
• Used for protein transport
• Surface area versus volume

Question 6

What is a genome?

Answer 6

Hereditary information, codes for all cellular structures

Consists of DNA, histones, and chromatin

Question 7

What is information transfer?

Answer 7

Ribosomes

The use of RNA in the formation of 50+ different kinds of proteins

Question 8

What’s an example of energy utilisation?

Answer 8

Harnessing of energy to build more complex components

Metabolism = catabolism + anabolism

Question 9

What is cytoplasm?

Answer 9

Semi-fluid, jelly-like

Embeds cellular components

Question 10

What are the domains of life base cell types?

Answer 10

Bacteria (prokaryote)
Archea (Prokaryote)
Eukaryote

Question 11

What is a nucleus?

Answer 11

Control centre

Structure = DNA, RNA, nucleolus, nuclear envelope, nuclear pores

Question 12

What is endoplasmic reticulum (ER)?

Answer 12

• An assembly line for protein and lipid synthesis
• Detoxification
• Structure = network of sacs

Question 13

What is the fucntion of the endoplasmic reticulum?

Answer 13

Rough ER = protein and ribosomes
Smooth ER = Lipids
Smooth + rough ER = continuous Ca2+ uptake/release

Question 14

What is the golgi apparatus?

Answer 14

Used for distribution and packaging of glycoproteins and polysaccharides

A stack of 4 - 10 discs covering three regions

Question 15

What are the names and functions of the three regions of the golgi apparatus?

Answer 15

Cis region = receives proteins/lipids from ER

Medial region = protein and lipid modification and maturation (glycosylation)

Trans region = glycoprotein and polysaccharides distribution via vesicles

Question 16

What are lyosomes?

Answer 16

The cleaning crew or intracellular recycling

They are membrane bound vesicles containing 40+ digestive enzymes

Question 17

What is the purpose and function of the mitochondria?

Answer 17

Powerhouse of a cell = source of energy production
(sugar + O2 = ATP + CO2 + H2O)

It has a double membrane (Outer = porin, Inner = electon transport)

Inside is the matrix = mixture of hundreds of enzymes, citric acid cycles, mtDNA, ribosomes, and tRNAs

Question 18

What is the form and function of the cytoskeleton?

Answer 18

Made up of microtubules, microfilaments, and intermediate filaments

Structures that help maintain cell shape and internal organisation

Also provide mechanical support that enables cells to carry out essential functions like division and movement

Question 19

What cell structures are unique to eukaryotes and which are unique to prokaryotes?

Answer 19

Eukaryote = nucleus, membrane organelles (ER, golgi apparatus, mitochondria, lysosomes, vesicles, etc), and cytoskeleton

Prokaryotes have a cell wall.

Question 20

Describe the evolution of eukaryotes with example

Answer 20

Eukaryotes are larger and more complex than prokaryotes, so it is likely they were prokaryotes that engulfed other prokaryotes and entered into endosymbiosis

Endosymbiosis = one provides the other cell with energy and receives protection and nourishment

Mitochondria is an example as it has evolved to hold its own DNA and creat eits own energy and is passed down from mother to mother to mother