hypertonic
A higher concentration of solutes
hypotonic
A lower concentration of solutes
isotonic
An equal concentration of solutes
Inorganic compounds
Make up non-living things, make up many essential substances such as water, hydrogen and carbon
Organic compounds
make up living things, contain carbon bound to hydrogen, elements arranged into large, complex chemical compounds which consist of monomers bound together to form polymers
Carbohydrates
serve as fuel and building material, consist of C, H, and O (H to O ratio is 2:1)
Lipids
contain C, H, and O, but in different ratios, rich energy source but difficult to digest, insoluble, long chains of fatty acid molecules and glycerol units
Nucleic acids
The subunit is the nucleotide (consists of sugar, phosphate, and nitrogenous base), they provide genetic instructions that code for proteins
proteins
Contain C, H, O as well as N, P, S, and other elements, Each molecule is a long chain of amino acid units (20 or so various kinds), can be denatured by heat, strong acids, ad bases
Monosaccharide
Simple sugars, are soluble and used in respiration, e.g., glucose
Disaccharide
Complex sugars, consist of two saccharide units bonded together, e.g., lactose
Polysaccharide
Long chains of sugar units, are insoluble and used for energy storage (e.g. glycogen and starch) and structural purposes (e.g. cellulose and chitin)
Carbohydrate examples
Sugar, celery, pasta
Lipid examples
Waxes (e.g., plant cuticles), Steroids (e.g., sex hormones), Pigments (e.g., chlorophyll), Phospholipids (e.g., cell membranes)
Nucleic acid examples
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
Protein examples
Enzymes, Hormones, Important blood proteins, Structural materials, Pigments
Monomers
Small molecules and building blocks for polymers
Polymers
Large molecules, made out of bonded monomers
Hydrolysis
The breaking down of polymers into monomers
Condensation
The bonding of monomers together to form polymers
Catalyst
A substance that speeds up a chemical reaction without being changed
Enzyme
A biological catalyst (usually a protein)
Substrate
The reactant molecules that an enzymes works on
Active site
The part of the enzyme where the substrate binds
Denature
Process of permanently modifying the structure of a protein (enzyme)
Factors affecting enzymes
there are many things that can affect the activity if enzymes, two of which are temperature and pH
Enzyme shape
the shape of enzymes is very important, the active site is extremely specific to the substrate that is acted on, this means that anything that causes the enzyme to change shape (denature) will stop it from working
Eukaryote cell
Has membrane bound organelles, multicellular, big, has a nucleus
Prokaryote cell
Doesn’t have membrane bound organelles, unicellular, small, doesn’t have a nucleus
Animal cell
Have centrioles, lysosomes, flagella
Plant cell
Have cell wall, chloroplasts, chlorophyll, large vacuoles
Cell/plasma membrane
helps to protect the cell, maintain their shape and keeps the cell from absorbing too much water, animal cells have an extracellular matrix that helps hold the cells together in tissues and protects and supports them
Cell wall
Only in plants, protects the insides and makes the cells rigid
Nucleus
Contains the cell’s DNA, the largest of all organelles, genes in the nucleus carry information necessary to make proteins, the nucleus is bordered by a double membrane called the nuclear envelope
rough endoplasmic reticulum
Synthesises an enormous variety of molecules, Then packages the molecules into transport vesicles, Rough due to ribosomes on the outer membrane, Ribosomes synthesis proteins
smooth endoplasmic reticulum
used for detoxification and makes some lipids, e.g., steroids
Golgi apparatus
Works in partnership with the endoplasmic reticulum, Refines, stores, and distributes the chemical products produced in the ER
Lysosome
A membrane enclosed sac, Contains digestive enzymes, Has three main functions: Fuse with food vacuoles to digest the food, Break down damaged organelles, Help destroy harmful bacteria
Vacuole
Membranous sacs used for storage (mostly in plants), Animals only have a few small vacuoles
Chloroplast
Only found in plants and algae, Sites of photosynthesis, Convert light energy to chemical energy
Mitochondria
The powerhouse of the cell, Sites of cellular respiration, Use glucose and oxygen to produce chemical energy (ATP), Found in all eukaryotic cells, CO2 + H2O -> C6H12O6+O2+H2O
Cytoskeleton
Not a true organelle, Network of fibres that Provide mechanical support and allow cells to change shape and move, Assist on cell division
Cilia and flagella
Are motile appendages, flagella propel the cell in a whiplike motion, Cilia move in a coordinated back-and-forth motion
Selective permeability
a property of cell membranes, membranes are said to be semipermeable., i.e., they allow certain molecules or ions to pass through.
Osmosis
the overall (net) movement of water molecules from a dilute solution to a more concentrated solution through a semi-permeable membrane.
Concentration gradient
The difference in concentration of molecules across a space
Limitations to cell size
A cell needs to be able to take in nutrients and eliminate wastes effectively. Since this mainly occurs via diffusion, factors that affect the diffusion will also affect a cells ability to survive
Chromatid
One of two duplicated chromosomes connected at the centromere
Centromere
Region of chromosome where microtubules attach during mitosis and meiosis
Cell cycle
Mitosis
a part of the cell cycle process by which chromosomes in a cell nucleus are separated into two identical sets of chromosomes, each in its own nucleus (diploid cells), a cell splits to create two identical copies of the original cell -> asexual reproduction
Interphase
The cell at rest, Accounts for 90% of the cycle, During interphase, the cell grows and copies its chromosomes in preparation for cell division
Prophase
Chromatin condenses into chromosomes, Nucleoli disappears, Each duplicated chromosome appears as two identical sister chromatids, joined at the centromere, Mitotic spindle begins to form, Centrosomes move to opposite ends of the cell, Nuclear envelope fragments, Microtubules extend from each centrosome and attach to the centromeres of the chromosomes
Metaphase
Longest state of mitosis, Centrosomes are at opposite ends of the cell, Chromosomes line up along the metaphase plate, an imaginary plane in the middle of the cell, Each sister chromatid is attached to a microtubule from the opposite side of the cell
Anaphase
Shortest stage of mitosis, Sister chromatids separate, each becoming a full-fledged chromosome, The chromosomes are then pulled to opposite ends of the cell, The cell elongates
Telophase
Two daughter nuclei begin to form in the cell, Chromosomes are decondensing, Cytokinesis is underway
cancer
begins when genes controlling cell growth and multiplication become mutated by carcinogens, One example is the p53 gene, which normally acts to prevent cell division in damaged cells
Rate of diffusion
Temperature – higher temp -> faster diffusion, Surface area – larger area -> faster diffusion, Concentration gradient – higher gradient -> faster diffusion, Size of particles – smaller particles -> faster diffusion, Diffusion medium – solid = slowest, liquid = faster, gas = fastest
Cell reproduction
Cell replication is a normal part of maintaining a healthy body, Growth, inheritance, and reproduction depend on cell division, Prokaryotic cells divide by binary fission, Eukaryotic cells divide by mitosis and meiosis
Chromosome replication
Before a cell can divide it must copy all of its chromosomes, Copied chromosomes remain joined and are called sister chromatids, Usually, chromosomes appear as chromatin but during cell division they become condensed packages so that they can be moved around easily, 46 chromosomes in each human cell
simple diffusion
Movement of solutes across the cell membrane with the concentration gradient between the phospholipid molecules.
facilitated diffusion
Movement of solutes across the cell membrane with the concentration gradient through the carrier proteins
osmosis
Movement of solvent (water) across the cell membrane with the concentration gradient between the phospholipid molecules and via aquaporins (protein channels)
ion pumps
Movements of substances against the concentration gradient through the carrier proteins
endocytosis
Bulk transport of liquids (pinocytosis) or solids (phagocytosis) into the cell
exocytosis
Bulk transport of substances out of the cell