Studying the Structure of Cells

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1.1 Studying the Structure of Cells

In 1665, English scientist Robert Hooke became the first person to study cells

Cell Structure

Nucleolus: Makes Ribosomes, which help to make proteins

Nuclear Membrane: Protects the contents of the nucleus

Nuclear Pores: Allow materials, such as ribosomes, in and out of the nucleus

|Light Microscope |Electron Microscope | |Uses light source |Beams of electrons focused by magnetic lenses| |Enable view to watch living cells |Produces an image of the shadows cast by | | |atoms of heavy metals; the living tissue is | | |destroyed by the intense beam of electrons | |Electron microscope has about 10,000 times the resolving power of the light instrument, and | |can therefore show far greater detail |

Cell Theory (made in the mid-1880s)

All living cells are made of one or more cells

The cell is the basic organizational unit of life
(all organism body functions are designed to supply the needs of its cell)

All cells come from pre-existing cells
(cell reproduction)

Cytosol: Fluid material between the cell membrane and the nucleus, filled w/ many specialized organelles

Animal & Plant Cell Organelles

All cells in your body depend on proteins

A number of the organelles are involved in the production, storage, or transport of proteins

Proteins are essential nutrients for the growth and repair of body tissues

All Cells Use Energy

Cellular Respiration: The process by which mitochondria releases energy from glucose

Cellular Respiration uses oxygen in order to occur
(we breath in air - containing oxygen)

Cellular Respiration produces carbon dioxide as a waste product when it releases energy (we get rid of Carbon Dioxide & water vapour when we breath out)

C6H12O6 Glucose + 6O2 Oxygen -> 6CO2 Carbon Dioxide + 6H2O Water + Energy that can be used by living things

1.2 Genes

The Nucleus: Control Centre of the Cell

Nucleus contains master set of instructions (chromosomes), determining: What each cell will become
How it will function
How long it will live before being replaced

Every plant and animal species has a specific number of chromosomes

Humans have 46 chromosomes (23 from each parent)

The DNA Code

Chromosomes come in parts
(One from each parent - when egg & sperm unite to produce a fertilized egg)

Every chromosome consists of a single molecule of DNA, which is divided into segments called genes

By controlling what proteins are made and when, chromosomes can control: cell activities
much of its structure

Double Helix: A twisted ladder shape of the Watson/ Crick model of DNA (1953)

Each piece of ladder’s side to which the rung is attached; is a building block molecule (Many building blocks strung together form a molecule of DNA)

Genetic Code: The order in which the A, T, C & G building blocks are strung together (Is different in every individual except in identical twins)

Genetic code is a message that determines the production of specific proteins - combining to make the organism function

Why is DNA Important?

Each DNA molecule contains hundreds/ thousands of genes

DNA exerts controls like the following - through genes
Features
Whether you can digest certain foods

Genes determine
what kinds of proteins your cells can make
therefore how your body might
function
look
life style choices (how much you eat & exercise)

Protein Production

Proteins get their orders from DNA

Each protein is designed to do a specific job
Help build parts of your body
Couriers - Carry materials short or long distances within your body Pickup/ Transfer...
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