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Flashcards in Biological Molecules Deck (50):
0

Water

- Low viscosity: water flows easily through blood vessels
- Transparent: light passes through easily - photosynthesis
- Universal solvent: can dissolve molecules
- Floats when solid, ice insulates water and keeps it warm

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Biomacromolecules

Organic molecules associated with living things.
Carbohydrates- carbon, hydrogen, oxygen. Glucose, mitochondria.
Lipids- Phospholipid bi layer
Proteins- Ribosomes, nucleus
Nucleic acids- Nucleus

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Carbohydrates

Contains carbon, hydrogen and oxygen
Roles:
Energy( ATP)
Energy storage (Starch)
Cellulose of cell walls of plants
Receptors on the cell membrane of cells

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Monosaccharides

One sugar unit
Eg. Glucose, fructose

4

Disaccharides

Two sugar units
Eg. Lactose, sucrose

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Polysaccharides

More than one sugar unit
Eg. Starch, cellulose

6

Lipids

Carbon, hydrogen, oxygen
- Chlorophyll is a lipid
- Phospholipid bi layer in a cell ( lipid tail part)

7

Triglyceride

Typical type of LIPID
- Consists of 3 fatty acids and glycerol
| |---
| |---
| |---

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Phospholipids

Can be made by removing a fatty acid from a triglyceride and adding a phosphate component

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What are the functions of fats and oils?

1. Energy storage
2. Cushions and insulates the body and nerves eg. Fats in myelin sheath
3. Forms key parts of cell membrane

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Proteins

Made up of amino acids
Roles: Enzymes eg. Lipase
Form structural components of cells eg. Cell membrane
Hormones eg. Insulin
Transport eg. Haemoglobin

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Proteomics

The study of proteins and their functions

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Proteome

All the proteins found in the human body

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Amino acids

Make up proteins
- 20 different types of amino acids
- All proteins contain carbon, hydrogen, oxygen and nitrogen

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Nucleic acid

Genetic material of all organisms
Two types: DNA and RNA
Determine features of an organism
Carbon, hydrogen, oxygen, nitrogen, phosphorus

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RNA

Found in nucleus and ribosomes
Function: To make ribosomes and involved in protein synthesis

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DNA

Found in nucleus, mitochondria( used to be unicellular organisms) , chloroplasts ( DNA from absorbed organisms)
Function: holds genetic material

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Nucleotides

Make up DNA and RNA

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Why are cells so small?

- Nutrients and waste move across a cell surface by diffusion
- Substances absorbed and waste removed
- As the size of an object increases the SA:V decreases

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What determines the rate of diffusion?

surface area

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Diffusion

Passive movement of a substance from a region of high concentration to one of low concentration.
No ATP used

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Osmosis

Passive movement of water from a dilute solution to a more concentrated.
No ATP used
Moves from lots of water to little water.

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Active transport

Movement of a substance from a region of low concentration to one of high concentration.
Requires energy ( uses ATP )

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Facilitated diffusion

Passive movement of a substance along the concentration gradient aided by protein transporters in the cell membrane.

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Concentration gradient

Gradual change in the concentration of a solutes in a solution as a function of distance through a solution.

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Exocytosis

Active movement of substances out of a cell by the use of vesicles that fuse with the cell membrane. Substances that cross the cell membrane by this method are often LARGE.

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Endocytosis

Substances entering a cell same way as Exocytosis
ACTIVE ( uses ATP )
Membrane surrounds substances and brings it into cell.

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Non-polar molecules

Fat based molecules can move easily through membrane (eg. Fatty acids)
Very small things ( oxygen, carbon dioxide, pure water )

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Polar molecules

Substances that dissolve in water eg. Glucose, nucleic acids, amino acids
Cannot move through a membrane so will come through by types of passive/ active transport

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Hypotonic

Dilute

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Hypertonic

Concentrated

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Isotonic

Balanced

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Enzymes

Enzymes act as biological catalysts that speeds up chemical reactions by lowering activation energy.

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Can enzymes be used over and over again?

Yes

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Activation energy

The initial input of energy into a chemical reaction

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Lock and key hypothesis

The fit b/w substrate and active site of enzyme is exact.
Enzyme=key
Substrate=lock
Explains enzyme specificity but does not explain how some enzymes can react with structurally similar substrates

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Enzyme-substrate complex

Temporary structure formed when active site and substrate fit together.

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Induced fit model

Substrate induces a slight change in the shape of the enzyme when it binds with it

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Co factor

Non protein substance that must bind to certain enzymes in order for that enzyme to work

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Co-enzyme

Organic co-factor

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Prosthetic groups

Permanently bonded cofactors

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Apoenzyme

Incomplete enzyme

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Holoenzyme

Whole enzyme

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Factors affecting enzymes

Substrate concentration
pH
Temperature
Inhibitors

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Limiting factor

Requirement in shortest supply

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Effect of pH

Extreme pH levels will denature an enzyme (above or below optimal pH)

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Effect of temperature

Too high a temp results in denaturation
Cooler temps slow down reactions

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Inhibitors

Chemicals that reduce the rate of enzymic reactions

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Competitive inhibition

Compete with substrate for the active site, if it's there then the substrate can't fit

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Non-competitive inhibition

Bind to the enzyme but not at the active site, results in a change of shape of the enzyme and the substrate can no longer fit in the active site