2 CELL THEORY All organisms are made of one or more cells. The cell is the basic unit of all living things.All cells come from existing cells.
3 CELL SIZELarge cellsChicken egg – doesn’t need to take in more nutrients.Small cellsMost cells are small because they need to take in nutrients and get rid of wastes. Volume of cell cannot be too large because the surface area will not be able to take in enough nutrients and expel waste fast enough.
6 EUKARYOTIC CELLSCell Wall – a rigid structure that surrounds the cell membrane and provides support to the cellCell membrane - protective layer that covers the cell’s surface and acts as a barrier to the outside environment. It also controls what goes in and comes out. Contains lipids (fat and cholesterol), proteins and phospholipids.
7 Cytoplasm – the fluid inside the cell Cytoskeleton – a web of proteins in the cytoplasm. Acts as a muscle and a skeleton. It helps some cells to move.
8 PARTS OF A CELLOrganelles – structures that perform specific functions within the cell
9 NUCLEUSDNA – (deoxyribonucleic acid) genetic material that carries information needed to make new cells and new organisms; it is also passed on from parent cells to new cells and controls activities of the cellNucleus – DNA is enclosed inside this organelle, it contains the genetic material to make cell proteins
11 NUCLEUSNucleolus – a dark area inside the nucleus that stores materials that will be used to make ribosomesRibosomes – organelles that make proteins; it is the smallest of all organelles. Proteins and RNA are made in the ribosomes (protein synthesis)Amino acids – building blocks of proteins; there are about 20 amino acids
12 ENDOPLASMIC RETICULUM Endoplasmic reticulum (ER) – a system of folded membranes in which proteins, lipids, and other materials are made.Substances move through these passageways to get to other cell partsMost chemical reactions occur hereRough ER – covered in ribosomes and near the nucleusSmooth ER – no ribosomes, makes lipids and breaks down toxic materials that could damage the cell
14 MITOCHONDRIA Main power source of the cell Sugar is broken down to produce energyEnergy release is stored as ATP (adenosine triphosphate)ATP is made in the inner membrane of the mitochondriaHave their own DNA
16 CHLOROPLASTS Found in plants and algae Photosynthesis takes place here Have 2 membranes and their own DNAContain chlorophyll (a green pigment)Chlorophyll traps energy of sunlight and uses it to make sugarThe sugar is then used by mitochondria to make ATP
18 GOLGI COMPLEX Packages and distributes proteins Looks like ER Lipids and proteins from ER are delivered to Golgi complexLipids and proteins are modified to do different jobsThey are then packaged and pinched off to form a small bubbleBubbles get transported to other parts of the cell
21 VESICLESVesicle – small sac that surrounds material to be moved into or out of the cell.Vesicles carry new protein from ER to Golgi complex
22 LYSOSOMES Vesicles that are responsible for digestion inside a cell Contains digestive enzymesDestroys worn out cell parts, get rid of wastes and protect cell from foreign invaders
23 VACUOLES A large vesicle Stores water Large in plants (if vacuoles lose water, the plant wilts)
24 ORGANIZATION OF LIVING THINGS Cell – (unicellular and multicellular)Tissue – group of cells that work together to perform a specific job (nerve tissue, muscle tissue, connective tissue and protective tissue)Organ – two or more groups of tissues working together to perform a functionOrgan system – a group of organs that work together to perform a functionOrganism – a living thing; anything that can carry out life processes independently
26 STRUCTURE AND FUNCTION Structure - the arrangement of parts in an organismFunction – the special, normal, or proper activity of an organ or part
27 DIFFUSION AND OSMOSISDiffusion – the movement of particles from regions of higher density to regions of lower densityOsmosis – the diffusion of water through a semipermeable (certain substances can pass through) membrane
30 Passive transport – the movement of substances across a cell membrane without the use of energy by the cellActive transport – the movement of substances across the cell membrane that requires the cell to use energyEndocytosis – the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cellExocytosis – the process in which a cell releases a particle by enclosing the particle in a vesicle that then moves to the cell surface and fuses with the cell membrane and releases it to the outside
33 CELL ENERGYPhotosynthesis: the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food.Pigment – molecules that absorb light energy.Chlorophyll is the main pigment that gives the plant its color.
41 CELL CYCLE Cell cycle – the life cycle of a cell DNA – (deoxyribonucleic acid) – the hereditary material of that controls all cell activities, including making new cells.Chromosomes – where DNA of a cell is organized; chromosomes are copied to ensure that each new cell is exactly the same as the parent cell
42 PROKARYOTIC CELLS Includes bacteria Have ribosomes and a single DNA moleculeDivides by binary fission(splitting into 2 parts)
43 EUKARYOTIC CELLSHomologous chromosomes – chromosomes that have the same sequence of genes and the same structureMitosis – in eukaryotic cells, a process of cell division that forms two new nuclei, each of which has the same number of chromosomes
53 HEREDITY! Gregor Mendel - born in 1822, in Heinzendorf, Austria he discovered the principles of heredity while he was in the gardenHeredity – the passing of genetic traits from parent to off-spring
54 SELF-POLLINATING PEAS Self-pollination - Has both male and female reproductive structures so it can pollinate itselfTrue-breeding – all off-springs will have the same traitsCross-pollination – when pollen from one plant will fertilize the ovule of a flower on a different plant (can occur by wind or insects).
55 Characteristics – a feature that has different forms in a population Characteristics – a feature that has different forms in a population. (ex-hair color)Traits – different forms of a characteristic (ex-brown hair)Dominant traits – the trait observed in the first generation when parents that have different traits are bredRecessive traits – a trait that reappears in the second generation after disappearing in the first generation when parents with different traits are bred
66 TRAITS and INHERITANCE Genes – one set of instructions for an inherited traitAlleles- one of the alternative forms of a gene that governs a characteristic such as hair colorPhenotype-an organism’s appearance or other detectable characteristicGenotype – the entire genetic makeup of an organism; also the combination of genes for one or more specific traits
67 Homozygous –a plant or organism with 2 dominate alleles or 2 recessive alleles Heterozygous – A plant or organism that has one dominate allele and one recessive allelePunnett squares – use to organize all possible combinations of offspring from particular parents
69 Probability – the likelihood that a possible future event will occur in any given instance of the eventIncomplete dominance – one trait is not completely dominant over another, so these traits blend
70 2 Ways to ReproduceAsexual reproduction – results in offspring with genotypes that are exact copies of their parent’s genotype; only one parent cell is needed (mitosis); most cells in your body reproduce this waySexual reproduction – offspring that share traits with their parents but are not exactly like their parents; two parent cells (sex cells) join together to form offspring that are different from both parents
71 MEIOSIS Human sex cells have 23 chromosomes (body cells have 46) Homologous chromosomes – chromosomes that have the same sequence of genes and the same structureMeiosis – a process in cell division which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells