Describe the structure of a water molecule
- made up of two hydrogen elements and one oxygen
- hydrogen and oxygen share atoms
- electronegativity of oxygen pulls atoms stronger to oxygen, giving hydrogen a slight positive charge and oxygen a slight negative one
- has a polar covalent bond
Describe the importance of the structure of water
- hydrogen from one molecule is attracted to oxygen of another molecule, due to the slightly positive and negative charge of each respected element (weak hydrogen bond)
- the charge on hydrogen allows it to easily bond to other molecules, especially
- its polar nature is the reason for it being a universal solvent, temperature regulator and its cohesive/adhesive properties
Describe the structure of a nucleotide
- Nitrogenous base
- Sugar
- Phosphate
Lost all polymers and their monomers
- Maltose: 2 glucose
- Lactose: 1 glucose and 1 galactose
- Sucrose: 1 glucose and 1 fructose
- Glycogen, Cellulose, Starches: chains of glucose
- Neutral Fat: 3 fatty acids and 1 glycerol
- Phospholipids: 2 fatty acids, 1 glycerol, 1 phosphate
- Proteins: amino acids
- Nucleic acid: nucleotides
What is the function of water
- used as a solvent in chemical reactions, dissolves products and transports them through the body
- aids in controlling body temperature
- lubricates and eases movement
- required for hydrolytic reactions in the body
Describe how hydrogen bonds can form between hydrogen molecules
- water is made up of 2 hydrogen atoms bonded to one oxygen atom
- both elements share electrons
- electronegativity pulls electrons closer to oxygen, giving it a slightly negative charge, and hydrogen a slightly positive one
- because of the two different charges, opposites attract, oxygen is attracted to other oxygen atoms
- forms a weak hydrogen bond
List the functions of a protein
- structural proteins (nails, hair)
- enzymes are used as catalysts for reactions in the body
- transport
- making antibodies to fight infection
What is the full name/location/function of ATP
- adenosine tri-phosphate
- made by mitochondria by burning glucose and oxygen
- supplies energy for all cells activities
List all the organelles and their function
•nucleus: control centre of cell, contains DNA
•nucleolus: contains specialized parts of chromosomes, involved in rRNA production
•cytoplasm: supports organelles
•ribosome: involved in protein synthesis
•rough ER: proteins move through rough ER to get to Golgi
•smooth ER: associated with lipid and steroid production, detoxifies cell
•vesicle: transports compounds within cytoplasm
•mitochondria: cellular respiration, converts oxygen and sugar to ATP
•Golgi body: takes materials from ER and packages them in vesicles
•Liposome: digest items in cell, destroys
pathogens and malfunctioning parts in cell
•microfilaments: provide skeletal support
•cilia/flagella: help with movement locomotion
Describe the inter relationship between the ER, Golgi and vesicles
Lipids and proteins are produced in smooth and rough ER, passed on to the Golgi body where it is modified for a certain purpose and packaged in to vesicles where they are sent out of the cell or somewhere else in the cell
Explain the inter relationship of vacuoles, cell membrane and lysosomes
Food vacuoles fuse with lysosomes which will digest the contents of the vacuoles. The waste produced will be packages into vacuoles which will fuse with the cell membrane to perform exocytosis
Describe active transport, some examples of molecules that move by active transport
- solutes move from an area of [low solute] to an area of [high solute] across a membrane with the aid of a protein carrier molecule and ATP.
- sugar is removed from urine by active transport, into the blood. Travelling across the concentration gradient
- Na+/K+ pump found in nerve and muscle cells
Define facilitated transport, osmosis, diffusion
- facilitated transport: solutes move across a membrane from area of [high solute] to an area of [low solute] with help of carrier molecule, no ATP
- osmosis: movement of water with concentration gradient through a semi-permeable membrane, no carrier or ATP required
- diffusion: movement of a solute with concentration gradient, no membrane, protein carrier or ATP required
List all the factors that affect the rate of diffusion
- temperature: higher temperature, higher rate of diffusion
- surface area: larger surface area, the higher rate of diffusion
- concentration gradient: greater c.g., greater rate of diffusion
- size of particles: the smaller the particle, the greater rate of diffusion (medium-sized particles diffuse faster in gas than liquid)
Describe hypertonic, hypotonic, isotonic
- hypertonic: solution with higher concentration of solute compared to another solution
- hypotonic: solution with lower concentration of solute compared to another solution
- isotonic: two solutions with the same concentration of solute to solvent
Explain DNA replication
- DNA molecule untwists with the help of Helicase (enzyme) breaking the bonds. Each side of the DNA molecule becomes a template. (Hydrogen bonds between nitrogenous bases are broken by Helicase)
- new complimentary nucleotides move in to place and match up with complimentary bases with the help of polymerase
- Ligase glues alternation sugar-phosphate backbone together
- two identical DNA strands are now present, they now twist back into helical shape
Describe the relationship of DNA to mRNA to tRNA
- mRNA is the messenger molecule that is made from a DNA template in the nucleus, so it can transport a coded message for protein synthesis to the site of protein synthesis in the cytoplasm
- amino acids are carried by tRNA to the mRNA on the ribosome to sequence the correct order in the growing protein as instructed by DNA
What is the purpose of transcription/translation?
- transcription builds a mRNA molecule, which is then transported into the cytoplasm to perform protein synthesis
- translation produces a protein molecule
Lock and key theory of enzyme activity
- active site of enzyme matches the specific shape of substrate
- bond together to form an enzyme substrate complex
- chemical reaction occurs and products are released
- enzymes can be reused
- enzymes speed up reactions and require less energy
Explain denature
- enzyme becomes malformed, causing the substrate to be unable to bond together.
- non-competitive inhibition: inhibitors change shape of enzyme, substrate can no longer bond
- drastic changes in ph change shape of enzyme
- excessive heat change shape of enzyme
List all factors that would affect enzyme activity and describe how
- competitive inhibitors block active site, substrate cannot bond
- temperature: cold will make reaction time slower, warm will make it go faster, excessively hot will denature enzyme
- ph: when ph moves from optimal level, enzyme will not work effectively/denature
- substrate concentration: higher [substrate], greater rate of reaction
- enzyme concentration: higher [enzyme], greater rate of reaction
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Chapter 3- Cell Structure19
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Chapter 4- Cell Membrane22
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Chapter 1- Cell Compounds3
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Chapter 2- Biological Molecules0
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Chapter 5- DNA13
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Chapter 6- Protein Synthesis27
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Chapter 7- Enzymes24
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Chapter 8- Digestive System28
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Chapter 9- Circulatory System0
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Chapter 10- The Heart0
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Chapter 11- Respiratory System0
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Chapter 12- Nervous System0
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Chapter 13- Divisions Of The Nervous System And Brain0
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Chapter 14- Urinary System0
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Chapter 15- Reproduction System0
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Unit 121
