Biology

Mitochondria – Cell’s Powerhouse. Provides energy – ATP (may provide extra to specialised cells performing multiple/complex functions). Inner folded crista – increases surface area for attachment of enzymes and their metabolic reactions.

Rough endoplasmic reticulum (ER) – Large surface area. That synthesis and transport of molecules around the cells. Covered in ribosomes.

Smooth endoplasmic reticulum (SER) – Produce, store and transport materials, no ribosomes.

Vacuoles – Sac storing different molecules. Small in animals – food storage and digestion and plants have large central vacuole used for storage of substances and control of water levels in the cell (osmotic balance).

Lysosome – Digestive enzymes, breaks down old cells, products, waste, and unwanted materials.

• Organelle – Cell structure that performs as a “tiny organ” to keep cells alive

• Nucleus –Contains DNA. Surrounded by Double membrane with pores – allows certain molecules in and out. nucleolus contains DNA and assembles ribosomes.

• Plant

specific: Chloroplast – Makes plants green. Site of photosynthesis

Photosynthesis Occurs (light

• Size between eukaryotic or prokaryotic cell – Eukaryotic (larger) contains membrane bound organelle – performs specialised roles and functions in cell. Prokaryotic (smaller) lacks membrane bound organelle.

• Why is there a size difference between eukaryotic and prokaryotic cells – Eukaryotic requires more complex functions – needs more cells to carry out different functions. Prokaryotic require one large cell to carry out all the responsibilities and functions.
• Size cells in multi vs unicells – Multicell require smaller cells. Because of large surface area as smaller cells are faster, more efficient and large area holds more smaller cells than larger ones

• The fluid mosaic model

Description of how molecules are arranged in the membrane

• Phospholipid bilayer

Molecule with negative charged phosphate “head” (hydrophilic

Protein channel types:
• Integral protein – Within membrane structure. Channel transport medium to large sized molecules and substances in and out. (highway).
• Peripheral proteins – Outside of membrane. Acts as receptors/messengers on what to let in and out. As well as respond to hormones or chemicals (guards).
• Protein channel = Integral channel – Others act as carrier molecules transporting specific substances through membrane.

• Glycoproteins – Proteins with polysaccharides (carbohydrates made of sugar). Signals tissue formation and cell

to cell communication. (instructor). Occurs in peripheral or integral protein.

• Cholesterol: Regulates fluidity of membrane, so cell functioning is neither too rigid/fluid.

Fluidity is temperature dependent (increased temp = increased fluidity).

Type of transport

Passive transport – Moves molecules across membrane (no energy)

Osmosis – movement of water through a selectively permeable membrane from LSC to HSC areas, to make it equal.

Osmosis potential:

1. Hypertonic: A solution with an HSC than its surroundings.

2. Hypotonic: A solution with a LSC than its surroundings.

3. Isotonic: A solution with an equal solute concentration to its surroundings.

• Carrier proteins: Change shape of molecule to fit easier and transport across bilayer.

• Active transport – Energy

consuming transport of molecules or ions across a membrane against a concentration gradient or an ionic gradient.

1. Specialised cells – Activating different genes to product different proteins during this process.

2. Tissues – Group of same specialised cells to perform certain functions, held by integral proteins.

3. Organs – Different tissues pulled together to perform certain functions.

4. Systems – Different Various organs work together to do assigned functions.

Cell Cycle:
Interphase
G0 – Temporarily stay for cells with lack of resources and requirements of stage.

1. G1 Phrase – Most time spent here for cells to grow to max size.

2. S Phrase – DNA pulled into threads (chromatin) condensed – forms chromosomes. DNA replication.

Chromatin: complex structure composed of DNA enclosed in protein.

3. G2 Phrase – Synthesis cells for additional copy of protein and organelles for cell division preparation. Protein stands form. Fibre spindles develop.

Mitosis:

1. Prophase – Condense chromosomes. Chromatid sisters come together. Nuclear and membrane of nucleolus dissolves. Fibre spindle form for structure creation.

2. Metaphase – Middle of cell, chromosomes align. Fibre spindles attach to centromeres.

3. Anaphase – chromatids sister pull to opposite poles of cells.

4. Telophase – chromatid sisters reach cell pole to unravel into threads of chromatin, and nucleolus and nuclear membrane reform.

Cytokinesis – Divides cells each daughter cell complete with cytoplasm, organelles and chromosomes

• Development stages in multicellular organism

Cells move to assigned places to begin forming multicellular organisms: cell proliferation, cell specialisation, cell interaction and cell movement.

Stem cells: Forms various types of cells

Zygote – egg fertilised

Differentiation – During development tissues, organs, and cells change

1. Self

renewal – Ability to go enter multiple cycles with no differentiation.

Factors that influence rate of reaction:
Concentration of reaction – Greater concentration – more likely to collide and react.
Temperature – Raising the temperature speed of random motion of molecules – increasing the probability of collision.

Enzymes – A catalyst is a substance that increases reaction rate without being consumed or changed by the reaction. Doesn’t change or get used up.
• An enzyme is named by adding the suffix “

ase” to the name of the subtracts on which it acts. For example maltase acts on maltose; lipase (lactose) acts on lipids
Subtract – Is the molecule(s) that an enzyme reacts with to form an enzyme

Factors that influence enzyme activity:
Temperature: Each enzyme has an optimum (highest) temperature. Which allows it to the work the best and most efficient.
pH: Each enzyme has an optimum pH and will only work within a narrow range of its optimum pH.
Substrate concentration: As substrate concentration increases the rate of enzyme action increases to a maximum value and then plateaus. If more substrate concentration is added after reaching maximum efficiency it will not increase reaction rate.

Inhibitors: Enzyme inhibitors are molecules that bind to an enzyme to reduce or prevent its activity.
2 main types:
Competitive inhibitors: Competes to the active site. Blocks it the substrate from entering
Non

competitive inhibitors: Doesn’t compete to the active site. Sits somewhere else that isn’t an active site.

THE DIGESTIVE SYSTEM:
Digestive tract
• Most animals have an alimentary canal

A muscular tube that runs through the centre of the animal and has two opening to the outside

Physical digestion – Breaking down of food in mouth. Increase in surface area to volume ratio

Mouth pH of 7.5

• Proteins

Macromolecule consisting of one or more polypeptide chains, containing C, H, O and N. -  Monomers/building blocks of proteins are called amino acids.

Chemical digestion – Is the process where food is broken down by digestive enzymes.

Stomach, gastric juice in stomach wall pH is 2

• Factors that influence enzyme activity

Temperature, pH, and substrate concentration. (increase rate of reaction, to max/optimum peak before declining - it will not increase after reaching max point)

what is the Digestive system - alimentary canal?

Most animals have an alimentary canal. which is a muscular tube that runs through centre of animal and has 2 opening to the outside.

• Chemical digestion

The process where food is broken down by digestive enzymes. occurs in the ileum ( forms smaller finger-like projections (villi))

The process of nutrients absorptions, assimilation and elimination:
• Absorption – Digestive molecules are small enough to move via diffusion, from the digestive tract to the circulatory (blood) system which transports them to the appropriate cells.
• Assimilation – Once inside the cells, the molecules then become part of a complex compounds of the body.
• Elimination – Undigested food is eliminated from the guts as faeces called egestion: removal of waste that was never part of the organism).

THE EXCRETORY SYSTEM:
Ureters – A pair of ducts that remove urine from the kidneys to the bladder.
Bladder – A membranous sac that stores urine.
Urethra – A duct the transports urine from the bladder to outside the body.

What is a eukaryotic cell?

Eukaryotic (larger) contains a membrane bound organelle and nucleus. can be both multicellular and unicellular. (house).

What is a prokaryotic cell?

Prokaryotic (smaller) lacks a membrane bound organelle and nucleus. Unicellular. (studio).

Why is there a size difference between eukaryotic and prokaryotic cells

Eukaryotic requires more complex functions – needs more cells to carry out different functions. Prokaryotic require one large cell to carry out all the responsibilities and functions

Size cells in multi vs unicells

·      Multi-cellular requires smaller cells. Because of large surface area as smaller cells are faster, more efficient and large area holds more smaller cells than larger ones

What type of channel is a protein channel and what does it do?

Integral channel – Creates a pathway for larger molecules, substances and ions to move through the membrane.

What is diffusion? what is the 2 types of diffusion?

-  Diffusion – Move molecules from HCA to LCA, no energy to create equal distribution.

o   Simple diffusion – Free and no help or energy movement of molecules from HCA to LCA.

o   Facilitated diffusion – With help of proteins moves molecules from HCA to LCA

What are the 3 types of osmosis potential?

1.        Hypertonic: A solution with an HSC than its surroundings.

2.        Hypotonic: A solution with a LSC than its surroundings.

3.        Isotonic: A solution with an equal solute concentration to its surroundings.

SA: Vol ratio and rate of diffusion

·      SA: Vol ratio – Large cells have a small SA: Vol. Small cells while large SA: Vol (better).

·      Rate of diffusion – Speed at which a substance diffuses in or out of a cell. This affects SA: Vol ratio

Process of organisation of multicellular organisms. cells to organisation (systems).

Cells:  

1. Cell movement: Cells move to assigned places to begin forming multicellular organisms.

2.   Specialised cells – Activating different genes to product different proteins and functions during this process.

organisation

1. Tissues –  Group of same specialised cells to perform certain functions.

2.  Organs – Different tissues pulled together to perform certain functions.

3. Systems – Different various organs work together to do assigned functions.

 

What is the (4) processes for the interphase stage (Cell cycle)?

Interphase

G0 – Temporarily stay for cells with lack of resources and requirements of stage.

1.        G1 Phrase – Most time spent here for cells to grow to max size.

2.        S Phrase – DNA pulled into threads (chromatin) condensed – forms chromosomes. DNA replication.

-              Chromatin: complex structure composed of DNA enclosed in protein.

-              Chromosomes – chromatin condensed fibres to design cell division process

3.        G2 Phrase – Synthesis cells for additional copy of protein and organelles for cell division preparation. Protein stands form. Fibre spindles develop.

What is the (4) processes for the Mitosis stage (Cell cycle)?

1. Prophase – Condense chromosomes. Chromatid sisters come together. Nuclear and membrane of nucleolus dissolves. Fibre spindle form for structure creation.

2.  Metaphase – Middle of cell, chromosomes align. Fibre spindles attach to centromeres.

3. Anaphase – Chromatids sister pull to opposite poles of cells.

4.  Telophase – Chromatid sisters reach cell pole to unravel into threads of chromatin, and nucleolus and nuclear membrane reform.

What happens during the Cytokinesis stage (cell cycle)?

Divides cells each daughter cell complete with cytoplasm, organelles and chromosomes

What does differentiation mean?

Process where a cell becomes specialised for a function. Through structures and genes.

What happens during self-renewal (stem cell)?

Produce and divide into more stem cells with no differentiation.

What is Potency (stem cell)?

Range and number of cell types a stem cell can form

What is Embryonic stem cell?

Undifferentiated cell in the early embryo.

What are adult cells?

Undifferentiated multi-potency int cell, responsible for repair and maintenance of the adult body

What are the four potency types? what cell types can each form?

·      Totipotent stem cells – forms any cells (including placental).

·      Pluripotent stem cells – forms into majority of cell types – except placental cells.

·      Multipotent – forms related-cell types. Commonly adult stem cells.

·      Unipotent – forms only one cell type and adult stem cell

inorganic vs organic

·      Inorganic – Non-living and non-carbon-hydrogen bound substances | Organic – living substances

What is a Macromolecule?

·      Large molecule. Play important role in biological processes.

   What are Saccharides?

· Single sugar molecules that make-up carbohydrates

·   How are Monosaccharide and Disaccharides linked?

Monosaccharide (1) Is a single sugar molecule. Linked together forms a disaccharide (2)

What are Polysaccharides (3 or more)?

·      Are long-chained carbohydrates that consist of multiple saccharides bonded together. Good storage and structural molecules. Readily convert to sugar when energy is needed.

What are Proteins? What do they consist of?

Macromolecule consisting of one or more polypeptide chains. Contains C, H, O and N

-              Monomers/building blocks of proteins are called amino acids.

What does Amino acids (NH₂) contain (4 levels)? What dimension does it stop at?

4 levels: Contains multiple bound amino groups, carboxyl group (COOH), R group, and hydrogen. it stops at a 3D shaped protein (active enzyme).

What’s a Carboxyl group (COOH)?

A variable group R (what makes them different) and a hydrogen group attached to a carbon atom.

What happens during denaturation (no enzymes)? why/when? also what does it mean in relation to enzymes?

Process which weak links or bonds in biological molecule breaks down. Exposed to high heat, strong acids/bases, organic solvents, heavy metals. Enzymes also stop.

What are Lipids?

(hydrophobic fats, oils and waxes). Energy stored phospholipid macromolecules to form cell membranes. Made up of fatty acids and glycerol. Contains C, H, and O. Length of carbon chain determines the type of lipid.

What are saturated and unsaturated lipids?

Saturated: Only single bonds between carbon atoms. More compact/solid, e.g. butter.

Unsaturated: One or more double bonds between carbon atoms. Less compact more tend to be like liquid – olive oil.

Structure of Triglycerides?

From one molecule of glycerol and three molecules of fatty acids.

What is Activation energy?

All reactions require specific amount of energy to start a chemical reaction. 

Factors that influence rate of reaction (3)?

1. Concentration of reaction – Greater concentration – more likely to collide and react.

2. Temperature – Raising the temperature speed of random motion of molecules – increasing the probability of collision.

3. Catalyst - Is a substance that increases reaction rate without being consumed or changed by the reaction. Doesn’t change or get used up.

Factors that influence enzyme activity (3)?

Temperature: Each enzyme has an optimum (highest) temperature. Which allows it to the work the best and most efficient.

pH: Each enzyme has an optimum pH and will only work within a narrow range of its optimum pH.

Substrate concentration: As substrate concentration increases the rate of enzyme action increases to a maximum value and then plateaus. If more substrate concentration is added after reaching maximum efficiency it will not increase reaction rate.

What are the two ezyme models? what does each suggest?

Lock-and-key model	Induced-fit model
A model that suggests that the substrate and antica site of enzyme are complementary in shape and fit together like a lock and a key.	A model that suggests that the active site of an enzyme, after initially attracting a specific substrate, changes to suit the substrate’s shape, which in turn also affects the shape of the substrate.

What is an inhibitor? What are the two main types?

Inhibitors: Enzyme inhibitors are molecules that bind to an enzyme to reduce or prevent its activity.

2 main types:

Competitive inhibitors: Competes to bind the active site. Blocks it the substrate from entering

Non-competitive inhibitors: Doesn’t compete to the active site instead binding to the allosteric site (not active site).

What is an alimentary canal?

A muscular tube that runs through the centre to the bottom.

What is Physical digestion? provide an example and its pH

Breaking down of food in mouth. Increase in surface area to volume ratio

-              Mouth pH of 7.5

What is Peristalsis?

Wave of contraction and relaxation in the muscular wars of the alimentary canal to move food down.

What is a Chemical digestion? provide 1-2 example and its pH

Is the process where food is broken down by digestive enzymes.

-              Stomach, gastric juice in stomach wall pH is 2

-              Pancreatic juice pH is 7 to 8.8

What are three enzymes? its function? and location?

Enzyme	Function	Location
Amylase	Breaks down complex carbohydrates to simple sugar molecules	Saliva and pancreas
Protease	Breaks down proteins into smaller molecules and amino acids	Pancreas
Lipase	Breaks down lipids into glycerol and small fatty acid	Pancreas

What does the small intestine absorb? what digestion occurs? What is microvilli?

·      Most absorptions of water and glucose occurs in small intestine

·      Chemical digestion occurs in the ileum

·      The inner surface of the ileum has folds which form smaller finger-like projections (villi)

·      The surface area is further increased by hair-like extension called microvilli.

What is the process of nutrients absorptions, assimilation and elimination?

·      Absorption – Digestive molecules are small enough to move via diffusion, from the digestive tract to the circulatory (blood) system which transports them to the appropriate cells.

·      Assimilation – Once inside the cells, the molecules then become part of a complex compounds of the body.

·      Elimination – Undigested food is eliminated from the guts as faeces called egestion: removal of waste that was never part of the organism).