Biology Midterm Review Modules 1-5

Mod 1 - Intro to Bio Mod 2 - Cellular Structure and Function Mod 3 - Microbiology Mod 4 - Tissues and Integumentary Mod 5 - Skeletal System + Review Questions

Define: Biology, Anatomy, Physiology

Biology: The study of all living things, including their structure, function, growth, and interrelationships.

Anatomy: The study of physical structures within an organism.

Physiology: The study of how those anatomical parts function individually as well as in conjunction with other structures of the body.

What are the 6 kingdoms? Describe characteristics of each.

1. Archaebacteria - Prokaryotic, unicellular organisms (most likely the first living cells on earth); compared to other prokaryotic organisms, they have very different DNA sequences, lipid structures, cell wall struct., and metabolism; found in extreme environments (e.g., hot springs, human digestive tract, etc.)

2. Eubacteria - Prokaryotic, single-celled organisms, though sometimes they cluster together (e.g., staphylococcus aureus); found in many different environments (including human body); a small % of bacteria can cause infections in humans (tuberculosis, salmonella, E. coli, chlamydia)

3. Protista - Mostly unicellular and eukaryotic; some species of protists are multicellular and very large (giant kelp); this kingdom’s organisms are the most numerous and diverse of any kingdom; found in any water environment; species in this kingdom can have features of the other 3 eukaryotic kingdoms, so they can be divided into fungus-like, animal-like, or plant-like; examples include algae, slime moulds, plankton

4. Fungi - Eukaryotic and multicellular (with exception of yeast, which is unicellular); not photosynthetic, most often absorb their nutrients from other organisms (such as trees or dead organisms); these organisms play an important role in decomposition and nutrient recycling; some fungi species used to produce antibiotics (like penicillin), while some can cause infections (like yeast infections)

5. Plants - Eukaryotic and multicellular; wide range of organisms, many of which are important food sources for us; plants have chloroplasts in their cells, which are membrane-bound organelles containing the pigment chlorophyll that is used in photosynthesis;

6. Animals - Eukaryotic, multicellular, and capable of locomotion

Describe the levels of organization from molecules à (?? prof did not check grammar)

Chemicals→Molecules→Cells→Tissues→Organs→Organ Systems→Organism

• Chemicals - individual elements (such as nitrogen, hydrogen, carbon, oxygen) combines to form↓

• Molecules - small molecules (glucose, water, amino acids, nucleotides) that combine to form macromolecules (complex carbohydrates, DNA, proteins, fats) and large macromolecules form part of every↓

• Cells - combine to form↓

• Tissues - such as epithelial, connective, muscle, and nerve; different combos of these tissues form↓

• Organs - composed of different amounts of all 4 tissue types; certain organs function with other organs and tissues to form↓

• Organ systems - such as digestive system, respiratory sys., etc.; all combined make up entire↓

• Organism

Define each of the anatomical terminological terms:

• Superior, inferior, anterior, posterior, proximal, distal, medial, lateral, intermediate, superficial, deep

• Body planes: parasagittal, midsagittal, frontal, transverse

Superior - Above, over, toward head

Inferior - Below, under, further from head

Anterior - In front, toward front of body

Posterior - Behind, toward back of body

Proximal - Closer to attachment point of a limb to trunk of body

Distal - Further from attachment point of a limb to trunk of body

Medial - Toward the midline

Lateral - Further from midline

Intermediate - In between 2 structures

Superficial - Toward surface of body

Deep - Toward interior of body

Parasagittal - Divides body into unequal left and right sections

Midsagittal - Divides body into equal left and right sections

Frontal - Divides body into anterior and posterior sections

Transverse - Divides body into superior and inferior sections

Name the body cavities and give examples of organs found in each.

Cranial cavity - brain

Vertebral cavity - spinal cord

Thoracic cavity - lungs, heart, trachea, upper esophagus↓

• also contains 2 other cavities: Pleural cavity (space between pleural membranes surrounding lungs); Pericardial cavity (space between pericardial membranes surrounding heart)

• the mediastinum (anatomical central region of thoracic cavity)

Abdominopelvic cavity (Abdominal cavity + pelvic cavity) - organs of digestive system, spleen, and the pelvic region (contains bladder, parts of large intestine, and internal repoductive organs)

How many abdominopelvic regions are there? Quadrants?

There are 9 abdominopelvic regions and 4 quadrants.

What are the properties of living things?

1. All living things are made up of the same macromolecules.

2. All living things have a cellular structure.

3. They grow and metabolize nutrients.

4. They have mechanisms of homeostasis.

5. They reproduce at a cellullar and organism level.

6. They have DNA that pass on through inheritance.

7. All species change over time through process called evolution.

Define homeostasis.

Homeostasis is the regulation of multiple factors within the internal environment of the body (textbook). OR homeostasis is the ability of the body to maintain a stable internal environment despite external fluctuations.

The internal environment is highly regulated so that the body’s cells function optimally. Homeostasis regulates factors mainly through a process of negative feedback.

What is negative feedback? Positive feedback? Which maintains homeostasis?

Negative feedback brings about a reverse in the level of a controlled factor (to bring it back to the set point).

Positive feedback continues to increase (enhance/amplifies) a response caused by an initial stimulation.

Homeostasis is primarily maintained by negative feedback.

What are the properties of water?

Water is a universal solvent and all living things are composed of anywhere between 45% to 95% water.

Healthy adult males are on average 60% water, healthy adult females are on average 55% (healthy females have slightly less water due to them carrying more body fat).

The polarity of water allows water molecules to form hydrogen bonds.

Define polar vs nonpolar and hydrophilic vs hydrophobic.

Any molecule or atom with slight charge is polar, so it can dissolve in water. Hydrophilic means “water loving”

Substances that do not have a charge are nonpolar, so they cannot dissolve easily in water. These molecules are hydrophobic “water fearing”

Both hydrophillic and hydrophobic molecules are essential to specific functioning of cells, the formation of cell membranes, and the ways that nutrients and wastes move across those membranes.

Sometimes molecules can have regions that are polar and regions that are nonpolar (phospolipids in cell membranes); these molecules are amphipathic (have both hydrophilic and hydrophobic components).

Define hydrogen bonds.

A (weak) bond between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom

Hydrogen bonds cause water molecules to form droplets and stay close together; this is called surface tension.

Which atoms make up living things?

1. Carbon

2. Oxygen

3. Nitrogen

4. Hydrogen

Define monomer, polymer.

Monomers are the building blocks of the many different types of proteins.

A polymer (AKA large macromolecule) is an assembled chain of monomers (all assembled the same way).

Describe the processes of dehydration synthesis and hydrolysis.

Dehydration synthesis is the reaction where monomers join together (to make a polymer) by losing a water molecule.

Hydrolysis is the reaction where polymers are broken down into monomers by the addition of a water molecule.

Describe proteins in detail including the following terms in your description:

• Amino acids

• Peptide bond

• Polypeptide

Proteins are complex macromolecules that are polymers made up of many subunits called amino acids (monomers). These assembled polymers are called polypeptides. For two amino acids to link together, covalent bonds are formed and these covalent bonds are called peptide bonds.

Simple description: Proteins are complex polymers made of amino acids linked together by peptide bonds to form long chains called polypeptides (proteins). (They perform structural, enzymatic, transport, and defensive functions - AI addition to describe proteins).

What structural components do amino acids have in common? How do they differ?

Amino acids all have a carboxyl group, an amino group, and a functional group. The functional group is what differs among all 20 amino acids (the functional group, also called R-group gives each amino acid its distinctive characteristics.

Describe the four levels of protein structure.

1. Primary - The sequence of amino acids in a protein (polypeptide chain); the formation of a specific protein requires the correct amino acids in the correct order, and the protein has to fold into the correct shape.

2. Secondary - As amino acids become arranged in correct order on the ribosomes in each cell, they take on a secondary structure (this is based on the interactions of the R-groups of the individual amino acids); hydrogen bonds form between polar amino acids, and hydrophobic amino acids attract other hydrophobic amino acids, allowing secondary structures to develop (I’m confused with this part, need to do more research to understand). Most secondary structures formed are called alpha helices or beta sheets.

3. Tertiary - The protein then takes on a 3-D shape based on the primary amino acid sequence and the secondary structures that are formed; the tertiary structure constitutes the functional structure of the protein.

4. Quaternary - Sometimes multiple tertiary structures combine to form a final functional protein product, called a quaternary structure.

Shortened:

• Primary: Linear sequence of amino acids in a polypeptide chain.

• Secondary: Local folding into alpha-helices or beta sheets stabilized by hydrogen bonds.

• Tertiary: Overall 3D shape of a single polypeptide chain formed by R-group interactions.

• Quaternary: Association of two or more polypeptide subunits into a functional protein.

Describe denaturation.

The unfolding or disruption of a protein caused by increased temperature or lower pH (or chemicals as well). These factors adds enough energy to break/affect the hydrogen bonds that form the secondary and tertiary protein structures.

Textbook: The process of breaking the interactions between functional groups in a protein is called denaturation. Denaturation is irreversible and denatured proteins no longer function (inactive) because their folded structure is critical for protein function. However, denaturation does not change the structure of individual amino acids.

What are the 2 nucleic acids? Describe the structure and function of them.

The 2 types of nucleic acids are:

• Deoxyribonucleic acid (DNA) - double helix (double-stranded); hydrogen bonds hold base pairs together; sugar-phosphate backbone (consisting of phosphodiester bonds) gives support, and the sugar (deoxyribose) connects to the base by a glycosidic bond. DNA stores genetic/hereditary information or is the “blueprint” for protein synthesis.

• Ribonucleic acid (RNA) - single-stranded and can have various folding patterns; the nucleotides are Adenine (A), Uracil (U), Cytosine (C), and Guanine (G); the sugar found in RNA is ribose. RNA is used as a template for protein synthesis (translates genetic information from DNA to build proteins).

What makes up a nucleotide?

Each nucleotide has 3 parts:

• Five-carbon sugar (ribose or deoxyribose)

• Phosphate group

• Nitrogenous base

What are the base pairs in DNA?

The base pairs between nucleotides (only 2 possible pairs) are:

• Adenine (A) with Thymine (T)

• Cytosine (C) with Guanine (G)

What is the difference between simple and complex carbohydrates?

• Simple carbohydrates: Monosaccharides (consist of only 1 monomer subunit) and disaccharides (consist of 2 monosaccharides) that provide quick energy.

• Complex carbohydrates (Polysaccharides): Long polymer chains (consist of more than 2 monosaccharides) of sugar units that provide sustained energy storage or structural support.

What are the 3 monosaccharides?

1. Glucose

2. Fructose

3. Galactose

What are the 3 disaccharides and what monomers make up each?

• Sucrose: Glucose + Fructose (table sugar)

• Lactose: Glucose + Galactose (milk)

• Maltose: Glucose + Glucose (grain)

Describe the 3 polysaccharides (complex carbohydrates) – starch, glycogen and cellulose.

• Starch - The stored energy in plant cells (starchy plant foods include rice, oatmeal, grains like corn, wheat, etc.).

• Glycogen - Stored energy in animal liver and muscle cells; can be used later when blood sugar levels start to decrease with exercise or in between meal.

• Cellulose - Structural plant carbohydrate not used to produce energy; when eating plants (like fruit, veggies, whole grains, etc.) we cannot digest cellulose. Cellulose is important as fibre. Consumption of fibre contributes significantly to our health (regulates bowel movement preventing constipation, prevention of bowel cancer, hemorrhoids, lowers blood cholesterol, regulates blood sugar).

Carbohydrates in diet are an important source of energy (or cellulose case, fibre).

What are the functions of lipids?

• Essential to brain function (fats compose 60% of brain)

• Proper organ functioning, cell flexibility, and building cell membranes

• Protect and cushion internal organs

• Allows fat soluble vitamins (A, D, E, K) to be absorbed (since fat has to be present)

• Proper immune system functioninf and help metabolism

Which monomers comprise fats (triglycerides)?

Glycerol and fatty acids (typically 3 fatty acids attached to 1 glycerol to form a triglyceride).

Compare saturated vs unsaturated fats vs trans fats.

• Saturated Fats: Only single bonds between carbons; solid at room temperature; straight chains. (e.g., butter)

• Unsaturated Fats: One or more double bonds; liquid at room temperature; bent chains. (e.g., olive oil)

• Trans Fats: Artificially altered unsaturated fats with trans-double bonds, making them solid and unhealthy. (e.g., processed foods)

What are essential fatty acids?

Essential fatty acids are fatty acids that the human body cannot synthesize on its own and must obtain from diet (e.g., Alpha-linolenic acid or Omega-3, linoleic acid or Omega-6, oleic acid or Omega-9).

Describe the structure and function of phospholipids.

Composed of a glycerol backbone, 2 hydrophobic fatty acid tails, and a hydrophilic phosphate/polar head (phospolipids are amphipathic). They form the primary lipid bilayer of cell membranes.

Their primary function is forming the structural basis of cell membranes, creating a semi-permeable barrier that separates the cell's interior from the external environment. This bilayer structure provides fluidity and flexibility.

What is the cell theory?

1. All living organisms are composed of cells.

2. The cell is the basic unit of all living organisms and the smallest single unit that can survive independently.

3. All cells come from pre-existing cells.

4. All cells contain genetic material (DNA), which is passed on to new cells that arise from cell division.

5. All cells are either prokaryotic or eukaryotic and are composed of basically the same types of phospholipids, proteins, carbohydrates, and nucleic acid molecules.

What is the difference between a prokaryote and eukaryote?

A prokaryotic organisms are simple, unicellular, and do not contain membrane-bound organelles such as a nucleus. Prokaryotes are generally termed bacteria.

Eukaryotic organisms are the opposite, in which they have complex cellular structures (contain various membrane-bound organells).

What are the names/functions of the organelles/cell structures discussed in class?

What are the cell junctions?

• Tight junctions: Hold some cell types together and prevent molecules from moving between cells, such as blood-brain barrier.

• Desmosomes: Anchoring junctions that anchors cells to the ECM (extra cellular matrix), found in cells such as skin that undergo a lot of stretching.

• Gap junctions: forms channels that allow direct communication and transfer of small molecules between cells.

Label a eukaryotic cell diagram.

• Nucleus (contains nuclear pore complex, nuclear envelope, nucleolus, chromatin)

• Rough endoplasmic reticulum

• Smooth endoplasmic reticulum

• Ribosome (and free ribosomes)

• Golgi complex

• Vesicle

• Mitochondrion

• Centrioles

• Lysosome

• Peroxisome

• Cytoskeletal proteins

• Cytosol

• Plasmic membrane

What are the types of cellular transport across the plasma membrane? Explain each in detail (diffusion, osmosis, facilitated transport, active transport, endocytosis, exocytosis)

Define hypertonic, hypotonic and isotonic solutions.

• Hypertonic: Higher solute concentration outside the cell, causing water to exit and the cell to shrivel (crenation).

• Hypotonic: Lower solute concentration outside the cell, causing water to enter and the cell to swell/burst (lysis).

• Isotonic: Equal solute concentration inside and outside the cell (cell stays the same).

What is a microorganism?

Also called microbes or microbial organisms, refers to all organisms that cannot be clearly seen with naked eye.

Have been around for billions of years b/c they are able to adapt to the ever-changing environment. Very abundant in environment as well as in and on our bodies. Important for food, drug industry (acts as decomposers).

What are the benefits of normal flora?

Normal flora aids in digestion, produce essential vitamins, train the immune system, and compete against harmful pathogens to prevent colonization.

In detail:

1. ferments indigested substrates (soluble fibre)

2. regulates immune system to tolerate food molecules

3. prevents growth of harmful bacteria

4. produces Vit. K and biotin

5. increases growth of intestinal cells and helps maintain healthy mucosal layer

6. produces lactic acid during fermentation (this lowers pH and prevents growth of pathogenic species)

7. converts carbohydrates into short-chain fatty acids that can be absorbed and used for energy

8. releases important minerals from food (like magnesium, calcium, zinc, iron)

9. metabolizes carcinogens by playing role in preventing colon, breast, and prostate cancers

Describe the structures found in bacterial cells. (ie. flagella, pili, endospores, etc)

• Protein Capsule: protection from environmental stress.

• Flagella: Long, thread-like outgrowths for mobility or swimming.

• Pili: Shorter outgrowths genetic material exchange.

• Endospores: Highly resistant, thick-walled, dormant structures allowing bacteria to survive extreme stress/changes in environment.

What is an opportunistic infection?

Opportunistic infections are caused by organisms that cause infection only when our immune system is suppressed or when our normal flora is damaged (after antibiotic treatment); they cause disease only when they have the “opportunity”.

Can be caused by bacteria, viruses, fungus, or parasites.

Why are viruses not considered living things?

Viruses are not considered living things b/c they only possess a portion of the properties of living organisms. They cannot reproduce independently (require a host cell), lack cellular membrane and organelles, their hereditary material can be DNA or RNA, and do not carry out independent metabolism.

Describe the lytic and lysogenic cycles.

Describe the characteristics of fungi and their beneficial/pathogenic properties.

• Fungi are eukaryotic and multicellular (except yeast are single-celled)

• Examples include: mushrooms, mold, mildew, yeasts

• Fungi live in soil, on plants, in air and water, and they play important role in decomposition and nutrient recycling

• Fungi can reproduce sexually or asexually; both involves production of spores (yeast reproduces by binary fission like bacteria)

• They usually do not cause severe infection in humans unless immune system is suppressed or there is breakdown in normal flora - opportunistic infections (can cause ringworm, candida albicans, etc.)

• Used for decades for their antimicrobial properties (for extracting antibiotics that fungi naturally produce to kill bacteria), and for producing vitamins and molecules used to treat cancer and heart disease

• Also used to make many foods (bread, beer, wine, kombucha, fermented foods)

Describe protozoa, including an example of a type of parasitic protozoan (described in class).

Describe helminths, including the different classifications (cestodes, trematodes and nematodes).

What are the four types of tissues and their functions?

The four types of tissues and their functions are:

1. Epithelial Tissue

2. Connective Tissue

3. Muscle Tissue

4. Nervous Tissue

Describe the structure and function of epithelial tissue.

How is epithelial tissue named? What are the types of epithelial tissue discussed in class?

Describe the structure and function of connective tissue.

What is the matrix? Ground substance?

Which protein fibres are found in connective tissue? What are their functions?

• Collagen: Most abundant protein in body; it is what makes tissue strong enough to withstand pressure.

• Elastin: The protein that gives tissues the ability to stretch and recoil back to original shape; connective tissues beneath epithelial cells of skin have high amounts of elastin.

• Reticular fibres: A type of thin collagen fibre surrounded by glycoproteins; these fibres form a framework for many tissues and acts as a filter in the spleen and lymph nodes; reticular fibres make up one layer (of the two layers) of basement membranes.

What three components make up connective tissue?

Connective tissue is composed of specialized cell types (combinations of different cell types), fibrous proteins, and ground substance.

How is connective tissue classified? Include a brief description of each of the types of connective tissue discussed in class.

What is the difference between neurons and neuroglia?

Neurons are the cells that send and receive signals, whereas neuroglia are the cells that supports the neuron cells.

What are the three types of muscle and their functions?

Describe the functions of the integumentary system?

• Protection provided by skin:

• Protection provided by hair and nails:

• Vitamin D synthesis:

• Excretion:

• Absorption:

• Regulation of body temperature:

• Sensation:

What are the skin layers? What are they made up of?

What are the layers of the epidermis from deepest to most superficial?

What are keratinocytes? Melanocytes? Langerhans cells?

What are the layers of the dermis?

What sensory receptors are found in the dermis?

What is the hypodermis?

The hypodermis (also called the subcutaneous layer) contains blood vessels, nerves, and adipose loose connective tissue (adipose tissue stores fat). It connects the dermis and epidermis to underlying muscle tissue. The hypodermis also provides insulation. (Hypodermis is NOT part of the skin)

What is responsible for the waterproofing of skin?

Sebaceous glands secrete oil “sebum” which lubricates outer layers of skin (epithelial cells) helping the skin act as a waterproof barrier

What are the types of glands found in the skin?

• Sudoriferous glands (sweat gands) - 2 types of these glands = eccrine and apocrine

• Sebaceous glands (oil glands)

• Ceruminous glands (produces ear wax)

• Mammary glands (produces milk)

Describe the types of skin cancer discussed in lecture.

• Basal cell carcinoma originates in the basal cells of the stratum basale of epidermis; most common type of skin cancer; caused by excessive sunlight exposure; appears as raised, smooth bump

• Melanoma is the uncontrolled growth of melanocytes; most dangerous type of skin cancer (if left untreated, can be fatal); rarest but highest mortality rate b/c can spread to other tissues; often arising from moles

• Not described in lecture but also, Squamous cell carcinoma; originates in keratinocytes of stratum spinosum layer; also caused by excessive sunlight exposure and can spread quickly if not removed (but easily treatable); appears red, raised, scaly patch and can grow if not treated

What are the functions of the skeletal system?

1. Provides structural framework for body

2. Provides movement b/c of attachments of skeletal muscles

3. Protects internal organs (such as brain, spinal cord, heart, and lungs)

4. Stores minerals (such as calcium, magnesium, phosphorus) and is involved in regulation of blood levels of those minerals

5. Produces red and white blood cells and platelets in red bone marrow by process called hematopoiesis

6. Stores fat as triglycerides in yellow bone marrow

What is the difference between spongy bone and compact bone? Include the differences in structure. (ie. osteons vs trabeculae, etc)

Describe the anatomy of a long bone.

Define the following:

Chondrocyte

Osteoblast

Osteoclast

Osteocyte

Define the following:

Osteon

Trabeculae

Canaliculi

Define the following:

Yellow bone marrow

Red bone marrow

What is the difference between the axial and appendicular skeleton? What parts of the skeleton are found in each?

The locations of the major bones described in Module 5 (ie. Label the skeleton diagram).

Which bone does not form an articulation with any other bone?

Which hormones are involved in the skeletal system? What are their functions?

What is unique about the atlas and axis?

What are the structural and functional terms to describe the articulations?

What are the types of synovial joints? What are the joint movements permitted by synovial joints?

Define the terms origin and insertion.