Biology Exam Review

Organic Compounds All living things are made of organic compounds. These contain the element Carbon The most abundant elements in living things are C, O, H, and N Organic compounds include Carbohydrates, Proteins, Lipids, Nucleic Acids

Carbohydrates Monomer- monosaccharide Function- energy source and structure Tests: glucose-Benedicts starch- Iodine fructose Ex. Cellulose, glycogen, starch

Lipids Made of fatty acids and glycerol Function- energy storage and insulation Tests: brown paper test Examples: fats and steroids Lipid vs. water

Nucleic Acids Monomer- nucleotide Function- carry genetic information Ex. DNA and RNA

Proteins Monomer- amino acids Function- building and repairing cells, communication, transport, and regulation Tests- Biurets Examples: enzymes, hemoglobin

Enzymes Catalysts in living things Specific to a particular substrate Reusable Affected by temperature and pH

Cells Prokaryotes Simplest cells Have no membrane bound organelles Have no nucleus Do have chromosomes, ribosomes, and plasma (cell) membrane Eukaryotes Do have membrane bound organelles Plants and Animals Have a true nucleus containing chromosomes

Nucleus “Control Center” Contains chromosomes

Mitochondria Singular: Mitochondrion “Powerhouse” of the cell Stores energy in the form of ATP Site of cellular respiration

Chloroplast Site of photosynthesis Plant cells ONLY Contains the pigment chlorophyll

Vacuole Storage of excess materials Plant cells usually contain one large vacuole

Ribosomes Proteins synthesis occurs here Very small organelles Found in ALL cells

Plasma Membrane aka: Cell Membrane Surrounds the cell Regulates what enters/leaves the cell Is called semi- permeable Helps maintain homeostasis (steady state) Made of phospholipids with embedded proteins

Cell Wall Plant cells ONLY Surrounds cell and provides support and protection. Made of cellulose

Differences in Plant and Animal Cells Plant Cell wall Chloroplast Large central vacuole Animal

Diffusion Form of passive transport (NO ENERGY NEEDED) across a membrane Solutes move from high concentration to low concentration Floating downstream

Osmosis Diffusion of water across a cell membrane from an area of high concentration of water to an area of low concentration of water (also passive transport) Floating downstream

Active Transport Particles moving against the concentration gradient which REQUIRES ENERGY (ATP) Low concentration to high concentration Swimming upstream

ATP Energy storing molecule Can be used for quick energy by the cell Energy is stored in the phosphate bonds

Carbon Cycle

Photosynthesis Water and Carbon Dioxide used to produce Glucose and Oxygen 6H 2 O+6CO 2  C 6 H 12 O 6 +6O 2 Occurs in the chloroplast Needs energy from the sun During photosynthesis, the absorbed sunlight energizes the chlorophyll.

Aerobic Respiration Used to release stored energy (ATP) for cellular use C 6 H 12 O 6 +6O 2  6H 2 O+6CO 2 Occurs in the mitochondria Both plants and animals use this process

Anaerobic Respiration aka Fermentation Does not require Oxygen also used to release energy, but not as efficient as aerobic respiration (less ATP) Products include CO 2 and lactic acid or alcohol Two Types: Alcoholic Fermentation and Lactic Acid Fermentation

Autotroph vs. Heterotroph Obtain energy from the environment Photosynthesis or chemosynthesis “Producers” Obtain energy from other living things “Consumers”

DNA / RNA Carry genetic information Made of a chain of nucleotides Nucleotides contain a sugar, phosphate, and a nitrogen base

DNA / RNA DNA Double stranded “Double Helix” Four base pairs: ATGC Sugar is Deoxyribose Found in nucleus RNA Single stranded Four base pairs: AUCG Sugar is Ribose

Base Pair Rule In DNA, Adenine always pairs with Thymine, and Guanine always pairs with Cytosine

Replication Making of an identical strand of DNA “semi” conservative New strand is complementary to old strand

Transcription DNA  mRNA Occurs in nucleus Complementary mRNA strand is produced from one segment of DNA

Translation Connects amino acids in the correct order to make a protein Occurs in the cytoplasm at the ribosomes A- amino acid B- tRNA C- anticodon D- codon E- mRNA F- Ribosome G-polypeptide

Codon Sequence of three mRNA nucleotides that code for an amino acid

Mutations Change in DNA code May cause a change in protein produced NOT always harmful Can be caused by an insertion or a deletion Frameshift-changes amino acid sequence Sickle Cell Mutation

Chromosomal Mutations More serious than point mutations Occur during mitosis or meiosis If occur in gamete (egg or sperm) can be passed down to offspring (children) If occurs in body cells, can cause cancer, be beneficial, or be neutral

Mitosis Cell division Produces two identical daughter cells Daughter cells contain same number of chromosomes as parent cell Occurs in body cells to grow and repair

Meiosis Cell division Occurs in sex cells (eggs and sperm) to form gametes

Phases of Mitosis Prophase, Metaphase, Anaphase, and Telophase Cell Cycle also included interphase and cytokinesis Interphase is when the cell is growing, making proteins, carrying out cellular respiration, etc. Cytokinesis is the process of actually dividing the cell into two parts.

Prophase Chromatin coils up into visible chromosomes Nuclear membrane disappears

Metaphase Chromosomes line up on the equator of the cell Are attached to the spindle fibers at the centromeres

Anaphase Centromere divides Spindle fibers pull the chromosomes toward the poles of the cell

Telophase Chromosomes reach the poles of the cell and start to unwind Cytokinesis occurs and the two cells begins interphase

Mitosis Place the pictures in order

Cancer Error in cell growth with causes uncontrolled cell growth Can be caused by exposure to certain chemicals (carcinogens), viruses (HPV) or to a mutation of the DNA

Genetic Disorders and the Environment Many diseases have both genetic and environmental factors Ex. Cancer, diabetes, PKU

Asexual vs. Sexual Reproduction Asexual (Mitosis) One parent Identical offspring (children) Variation only thru mutations Sexual Two parents Offspring (children) different from parents More genetic variation

Biotechnology Involves changing the DNA of an organism Can involve plants, animals, or bacteria

Recombinant DNA Cell with DNA from another source Bacteria used to produce human insulin Human gene inserted into bacterial DNA

Transgenic Organism An organism with a gene from another source Used to improve food supply, resistance to insects, and healthcare

Clone An organism made from one cell of another organism A genetically identical copy

Stem Cell Research Use of undifferentiated cells from human embryos to cure genetic diseases Undifferentiated cells can become any type of cell This is banned in the US because …..

Biotechnology All examples of biotechnology have positive aspects such as –Increased crops –Better disease resistance –New drugs and treatments Negative aspects –Reduces genetic variation

Cell Theory All organisms are made up of cells. All existing cells are produced by other living cells. The cell is the most basic unit of life. Spontaneous generation –Mice came from wheat and sweaty shirts –Flies came from rotting meat

Microscopes Light Microscope Cheaper to buy Produces less magnification so shows less details Can be used with dead or living samples Electron Microscope More expensive Produces greater magnification so shows more details Can only be used with dead samples

Parts of Brain Cerebrum Cerebellum Pons Medulla Oblongata

Lobes of Cerebrum Remember Flowerpot- F P O T

Plants Multicellular eukaryotes Autotrophs Reproduce sexually and asexually Have three main parts –Roots –Stems –Leaves

Stem Designed to support the plant Transports materials between the leaves and the roots Xylem carries water and nutrients from the roots to the rest of the plant Phloem carries the glucose down from the leaves to the rest of the plant (flows downhill)

Leaves Part of the plant with the greatest number of chloroplasts Where photosynthesis occurs Shaped to absorb more sunlight

Roots Absorb water and nutrients from the soil Hold the plant in place

Two Types of Root Systems Fibrous Roots Shallow branching mesh of small roots Tap Roots Long straight root with few branches Think carrot

Cohesion and Adhesion Cohesion- attraction between water molecules Adhesion- attraction between water molecules and other molecules

Water Movement in Plants

Parts of Flower Petal of flower is brightly colored to attract insects Pistil collects the pollen and passes it to eggs in the ovary Stamen produce the pollen (sperm ) Ovary is where the embryo develops after the egg is fertilized

Scientific Method

Experimental Variables Independent Condition you are changing in the experiment Plotted on the Y axis Comes after the “if” in your hypothesis Dependent Condition that you are measuring in the experiment Plotted on the X-axis Comes after the “then” in your hypothesis

Constants and Controls Constants Conditions in the experiment that you are keeping the same Control Group of similar subjects to which you compare your experimental group

Hypothesis If…. Then …. Statement that you write BEFORE your experiment Allows you to predict what your results will be

Theory A proposed explanation for a wide variety of observations and experimental results Can NEVER be proven Can be revised if new experimental results can’t be explained by it

Peer Review Other scientists try to duplicate your results Confirms your results Helps science move forward because it can encourage other scientists to look at the question in a new way

Homeostasis Steady state- trying to keep conditions from changing

Properties of Water Heat capacity- ability of water to moderate temperature This means it keeps the temperature from changing quickly