Download Unit 3 Biology - moleculesoflife2

Unit 3 Biology
Study 1
Molecules of life
Name:…………………………
Text: Heinemann 2. 4th Edition
Cells
Cells – The basic unit of life. Atoms are the basic building block of matter and they
create cells. Cells are the result of chemical compounds being formed for a purpose.
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The cell theory states:
All organisms are composed of.…………………..and their.…………………………
All cells come from pre-existing cells
The cell is the smallest …………………………………………………………… unit.
All cells perform similar ………………………and some have specialised functions.
Cell activities are carefully regulated and are ………………………… by enzymes.
Cell structure
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There is no such thing as a……………………cell but all cells share some features.
The cytoplasm is enclosed within an outer plasma………………………………..
that separates it from its environment and contains the genetic material.
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Two main types of cells: ………………………….and………………………………….
Prokaryotes
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These include……………………………and…………………………………………….
These are small and…………………………………………..membrane organelles.
Have a………………………………….circular DNA chromosome.
The plasma membrane is surrounded by an outer …………………………of protein
and complex carbohydrate.
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The cell wall in plants is composed of………………………………….and in fungi;
the cell walls are composed of…………………………………..
Eukaryotes
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These have an……………………………….membrane system that forms a nuclear
membrane and membrane around other organelles.
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Eukaryotes develop into multicellular organisms and are often referred to as
“………………………..…..”
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Prokaryotes are sad to have been the precursor to eukaryotes according to the
evolutionist theory.
Cellular chemistry
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There are…………………………………naturally occurring elements.
C, H, O, and N make up………………………………of an organisms weight.
Atoms are the basic unit of all………………………….
Substances consisting of only one kind of atom are called………………………….
Molecules are………………………………or more of the same (or different kind) of
atoms held together by…………………………………….bonds.
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A compound is a……………………………..containing more than one type of atom.
Chemistry of cells
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These have an outer membrane known as a plasma membrane.
DNA is located in a………………………contained with a nuclear membrane.
DNA is formed into………………………like structures known as……………...
Organelles are…………………………………in a membrane.
Organelles are subcellular structures that carry out a specific function.
Note: Plant cells and prokaryotes have a……………………... Animal cells do not.
Water
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Most organisms have………………………….water in their makeup.
Cellular activities occur in a……………………………..environment.
The water in organisms needs to have the correct pH, ion concentration,
temperature, salinity and degree of………………………………...
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Oxygen is not very…………………………….in water. That is why fish require gills.
………………………………….is the key atom in organic molecules. Plants take
this from the air during photosynthesis
Nitrogen
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Nitrogen is required in large amounts by all organisms to make……………………..
Atmospheric nitrogen (78% is found in the air) is taken in by bacteria during
“…………………………….” and is then directly taken up by plants through their
roots.
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Symbiotic……………………….are located on the roots of plants and are vital in
this process.
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Other useful minerals include phosphorous, potassium, mg, Na, S, and I.
Humans require at least …………………………….different mineral types.
Carbohydrates
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There are 4 main types of……………………………….molecules. These are
carbohydrates, lipids, proteins and nucleic acids.
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Carbohydrates – Stored as starch for energy in plants, structural cellulose in plants
and glycogen in animals.
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Carbohydrates are made from ………………………………………
Monosaccharides are single sugars such as ……………………………
Disaccharides = two sugars
Polysaccharides = many sugars
Lipids
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Lipids are fatty substances and include……………………. and……………….. They
are energy rich (………………per gram).
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Made from C, H and O. Similar to Carbohydrates but in……………………………
proportions and can have other elements such as N and P added.
Proteins
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Proteins are the most ………………………of the ……………………….compounds.
Proteins are made from C, H, O and………………………….
They are made from sub units known as ………………………. There are 20
different types of amino acids.
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In medicine,…………………………………….of all drugs are proteins.
Examples of proteins include hormones, enzymes and blood hemoglobin.
They are used to build cell structure.
Nucleic acids
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Nucleic acids are the………………………………material of all organisms.
Two types include DNA (deoxyribonucleic acid) and RNA. (…………………………)
Both are created from long chains of units known as ………………………….
DNA carries genetic instructions required to ………………………….the proteins.
RNA plays a major role in the building of proteins on organelles known as
ribosome's found in cells.
Protein structure
Proteins are amino acid……………………………….that fold into unique 3
dimensional structures. The shape into which a protein naturally folds is
known as its ……………………….., which is determined by its sequence of
amino acids. Thus proteins are known as …………………………, with amino
acids being the monomers. Biochemists refer to four distinct aspects of
protein structure.
1. Primary structure. – The amino acid ……………………………..
2. Secondary structure – highly patterned ……………….. (Alpha helix,
beta sheet, or segments of chain that assume no stable shape)
3. Tertiary structure – the overall ………………………or…………………
that results from the union of more than one protein molecule,
4. Quaternary structure – the shape or structure that results from the
union of more than one…….………………………., usually called
subunit proteins.