Human Biology Study Guide - Unit Test 1 PDF

101-901-VA Human Biology / 101-401-VA The Human Body ==================================================== Study guide -- Unit Test 1 ========================== Humans in the World of Biology ------------------------------ ### Major functional characteristics of life 1-Made of cells and basic nut...

101-901-VA Human Biology / 101-401-VA The Human Body ==================================================== Study guide -- Unit Test 1 ========================== Humans in the World of Biology ------------------------------ ### Major functional characteristics of life 1-Made of cells and basic nutrients (proteins, carbohydrates, lipids & nucleic acids) 2- Innate Order: Atoms -\> complex molecules -\> tissues -\> organs -\> organisms 3- Grow & Reproduce 4- Use Energy and Raw Material 5- Responsive to environment 6- Maintain homeostasis 7- Evolve and have adaptive traits 8- Death ### Level of biological organization: -from simplest to most complex\ -from least to most inclusive Atom: Smallest unit of matter Molecule: Made up of multiple atom into a functioning entity Organelle: multiple molecules working together for a function inside of the cell Cell: Multiple organelles working together to form a specific type of cell (e.g. skin cell, neuron, muscle,..) Tissue: Multiple cells of the same type (e.g. muscle cells) working together for a specific fu nction Organ: Multiple tissues working together for a specific fonction Organ system: Multiple organs working together for a specific fonction Organism: The summation of the multiple organ systems present in the body ### Scientific method 1.Observe (curiosity -\> questions -\> how? why? what? when? where? who?) 2\. Hypothesize (i.e. possible answer which can be tested) vs Null Hypothesis. 3\. Design experiments where you can predict outcomes that support hypothesis (or eliminate null) 4\. Do results support hypothesis? Stat results give a **p-value** which is the probability that differences seen can be attributed to chance. In biology, we consider a **[\ CANNOT DIGEST  #### Proteins - Chain of amino acids (AAs) also called a polypeptide - The variety of structures of protein is due to the different atoms in the different amino acids. - This leads to different structures for different tasks. #### Lipids - All hydrophobic and not soluble in water - Most lipids have 2 or 3 Fatty Acid chains linked to a glycerol molecule Three main types of lipids: 1\. Fats (oil, animal fat) - Primary stored energy is body fat - Carry fat soluble vitamins (A, D, E, K) - Component of cell membranes - Helps in production of hormones and Vitamin D - Body protects internal organs and insulates the body against temperature extremes 2\. Steroids - Cholesterol is basic precursor molecule - They are very important in the structure of cell walls & in secondary sexual characteristics. 3\. Phospholipids - Have a hydrophilic \"head\" containing a phosphate group and two hydrophobic \"tails\" derived from fatty acids, joined by an alcohol residue - Main component of the cell membrane #### Nucleic acids (DNA and RNA) - DNA -codes for all genes - When protein needed, the right gene is copied -\> mRNA - mRNA goes out of nucleus into cytoplasm to ribosome where a particular protein is made from the code - Which genes are copied determines which proteins are made The Cell -------- ### Cell theory - Structural and functional **unit of life** - The body depend on individual & collective cell functions - **Complementarity of structure & function =** biochemical activities of cells dictated by their shapes or forms, and specific subcellular structures All cells have some common structures & functions - All cells have **[4 basic components]**: 1. **Plasma membrane -**flexible outer boundary 2. **Cytoplasm** -intracellular fluid containing organelles for different functions 3. **Nucleic acids** --genetic info 4. **Ribosomes** for protein manufacture Prokaryotic cell: Only plasma membrane, DNA region (or nucleoid region), cytoplasm, ribosome and cell wall. We will focuse on the eukaryotic cell ### Eukaryotic cell components #### Plasma membrane - Main function: -separates **inside** from **outside** of cell - Main structure is lipid-based (phospholipids) + proteins to control what goes in & out. - **[Proteins]** allow communication with environment & other cells ##### Cross cell transport Most things are small and move in and out of cells - - **NO ENERGY REQUIRED** ##### Vesicular transport - - **NEEDS ENERGY!** - - - - #### Nucleus - - #### Ribosomes - - #### Endoplasmic reticulum (**rER & sER)** Two types of endoplasmic reticulum: - **Rough endoplasmic reticulum** (**[rER]**) - "rough" part is due to ribosomes on membranes - guide the production of proteins for export out of the cell - **Smooth endoplasmic reticulum ([sER])** - no ribosomes - Is involved in the production of membranes and for detoxification #### Golgi complex/apparatus/body - **Proteins made in rER --\> Golgi --\> to cytoplasm OR to PM & outside of cell** #### Lysosomes - Bud off Golgi - filled with hydrolytic enzymes & acid interior (pH 5.0) - Function: digest macromolecules down to their monomers #### Mitochondria - Sites of cellular respiration - Provide cell with energy through the breakdown of glucose to produce ATP using oxygen #### #### Cytoskeleton - gives cell its shape - helps keep organelles in position - aids in cell [movement (ex. Flagella and cilia)] - aids in [internal transport] system (via vesicle movement) Chromosomes and Cell Division ----------------------------- 2 types of cell division: mitosis & meiosis +-----------------+-----------------+-----------------+-----------------+ | | **Role** | **Outcome** | **Where** | +=================+=================+=================+=================+ | **Mitosis** | for growth, | creation of | Occurs in | | | repair & | genetically | **somatic** | | | replacement of | identical | cells (all | | | cells | diploid cells | cells except | | | | | germ cells) | +-----------------+-----------------+-----------------+-----------------+ | **Meiosis** | for the | reduce \# of | In females | | | creation of | chromosomes by | Occurs in | | | haploid gametes | ½ (haploid) & | ovaries | | | (eggs & sperm) | mix DNA of | (**oogenesis**) | | | | original | eggs | | | | parents | | | | | | In males Occurs | | | | | in testes | | | | | (**spermatogene | | | | | sis**)sperm | +-----------------+-----------------+-----------------+-----------------+ ### Diploid vs Haploid Somatic cells (most body cells) are **diploid (=2n)** i.e. have **2 sets of chromosomes** Gametic cells(egg or sperm) -have **only 1 set (haploid=1n)** **Fertilization** of egg by sperm re-establishes diploid state(**2n**) #### Human life cycle 2 types of cell division needed ### Chromosomes - - - - - - **Each cell contains 2 chromosomes** with genes for the same traits: **One chromosome of the pair is from the mother** **One chromosome of the pair is from the father** Determine expression of most of a person's inherited characteristics Of the 23 pairs of chromosomes **[Sex chromosomes]** make up one pair: Determine biological sex **[Autosomes]** make up other 22 pairs ### Mitosis Cell Cycle \| Brent Cornell  #### Checkpoints for cell cycle Control of the Cell Cycle -- MHCC Biology 112: Biology for Health Professions ### Meiosis (Sexual reproduction) - Allows the **mixing** & **matching** of genes from 2 **individuals**. - MEIOSIS [= cell division for the] [formation of gametes (egg or sperm)] ½ the original \# of chromosomes original DNA mixed  #### How do we get more genetic diversity during meiosis? **[Sexual reproduction]** results in shuffling of genetic information in a population. So, no two individuals have exactly the same genes. Done by **Crossing over** & **independent assortment** of chromosomes. **Crossing over** - 19\_13Figure-L **Independent assortment** - -  #### When things go wrong -- Non-disjunction **Failure** of homologous chromosomes **to separate**. Results in too many or too few chromosomes in a cell. Can lead to abnormalities in development (e.g. Down Syndrome) or miscarriages. 19\_15Figure-L #### Cell cycles in humans Developing embryo and fetus - Body cells divide continually (by mitosis) Children - Body cells divide for growth and repair (by mitosis) Adults - Some cells lose ability to divide (ex most neurons) - Some cells stop dividing but retain ability to divide should the need arise (ex liver cells) - Some cells actively divide throughout life (ex skin cells) - Germ cells divide for eggs or sperm. (by meiosis)  ### Cell death **Necrotic** (dying) cells are damaged or starved for oxygen or nutrients. The cell swells and bursts. - Cell contents are released to the extracellular environment. Can cause inflammation. **Apoptosis** : Genetically programmed cell death **[Two possible reasons:]** - Cell is no longer needed, ex: the connective tissue between the fingers of a fetus in development. - Old cells may be prone to genetic damage; ex. blood cells & skin cells die after days or weeks so as to be replaced with new healthy cells. - some mutated cells simply cannot survive ### Uncontrolled cell division **Benign tumor** - Abnormal mass of tissue surrounded by a capsule of normal tissue - Usually remains at the site where it forms - Often can be removed completely by surgery **Malignant tumor** - Invades surrounding tissue - Spreads to multiple locations (= **metastasis**) **Cancers** - Can be due to DNA damage (multiple mutations). Can be due to viruses or by exposure to chemicals or radiation - Development of cancer is a multistep process involving **multiple mutations in the same cell. Damage must occur in at least two alleles of the same gene.** - Mutations can be genetically inherited -\> **can speed up the process because every cell of the body has the 1^st^ "hit"** What Is Cancer? Symptoms, Causes & Types