BIO 1010 Unit 3 Exam

Cell

The smallest structural and functional unit of an organism; capable of preforming all processes neccesary for life

Robert Hooke

Who discovered cells in plant cell walls in 1665?

Anton Van Leeuwenhoek

Who first observed single celled organisms in 1675?

Cells are the most basic unit of life

What is the first rule of cell theory?

All living organisms are composed of one or more cells

What is the second rule of cell theory?

All cells arise from pre-existing cells

What is the third rule of cell theory?

Matthias Schleiden and Theodor Schwann

Who proposed cells are the basic unit of life and co-founded cell theory in 1838?

Rudolf Virchow

Who proved that cells replicate through division in 1885?

Light microscopy

A type of microscopy that uses visible light and lenses to magnify the details of an object

Electron microscopy (TEM and SEM)

A type of microscopy that uses electron beams to provide detailed imaging of cell structure and organelles

Cell fractionation and centrifugation

Techniques used to separate cellular components based on size, density, and solubility

Surface area to volume ratio

Aspect of cells that influences cell metabolism, nutrient exchange, and waste removal; As cells grow larger, their volume increases more rapidly than their surface area

Prokaryotic

Prokaryotic or Eukaryotic?

Does not contain a nucleus

Prokaryotic

Prokaryotic or Eukaryotic?

Lacks membrane bound organelles

Prokaryotic

Prokaryotic or Eukaryotic?

typically smaller; 1-10 micrometers

Prokaryotic

Prokaryotic or Eukaryotic?

Contains 70s ribosomes

Prokaryotic

Prokaryotic or Eukaryotic?

Reproduces through binary fission

Eukaryotic

Prokaryotic or Eukaryotic?

Contains membrane bound organelles and linear DNA inside a nucleus

Eukaryotic

Prokaryotic or Eukaryotic?

Has a complex structure with cytoskeleton

Eukaryotic

Prokaryotic or Eukaryotic?

Typically larger in size; 10-100 micrometers

Eukaryotic

Prokaryotic or Eukaryotic?

Contains 80s ribosomes

Eukaryotic

Prokaryotic or Eukaryotic?

Reproduces through mitosis and meiosis

Stem cells

Undifferentiated cells with the ability to differentiate into specialized cell types; important for development, tissue repair, and regenertion

Embryonic stem cells

Stem cells found in embryos that are capable of developing into any cell type

Adult stem cells

Multipotent stem cells found in various tissues, important for repair and regeneration

Apoptosis

Programmed cell death

Scanning electron microscopy (SEM)

Electron microscopy that captures detailed surface structures.

Transmission electron microscopy (TEM)

Electron microscopy that focuses on internal structures

Plasma membrane

Cell structure that is selectively permeable and controls what goes in and out of the cell; made up of a phospholipid bilayer

Cytoplasm

Gel like structure within the cell that contains organelles, cytoskeleton, and various molecules

Ribosomes

Cell structure composed of rRNA and proteins; site of protein synthesis

Free in the cytoplasm or bound to the ER

Where are the ribosomes found?

Nucleus

Organelle with a double membrane structure (nuclear envelope) and nuclear pores; contains chromatin; houses genetic material + regulates gene expression

Nucleolus

Organelle within the nucleus; site of ribosome assembly (rRNA synthesis and ribosomal subunit assembly)

Endoplasmic Reticulum (ER)

An extensive network of membranes found in Eukaryotic cells; involved in the synthesis, folding and modification of proteins, calcium storage and release, and drug metabolism and detoxification

Rough ER

ER studded with ribosomes; involved in protein synthesis

Smooth ER

ER without ribosomes; involved in lipid synthesis, metabolic processes, and detoxification

Golgi Apparatus

Organelle made up of a stack of vesicles; involved in processing, packaging, and shipping of cellular products

Cisternae

The flattened sacs that make up the golgi apparatus

Glycosylation

One way that the golgi modifies molecules

Vesicles

Small membrane bound stack that transport substances within the cell

Vacuoles

Large membrane bound sacs in plant and fungi cells; Store water, ions, nutrients, pigments, and contribute to cell structure

Central vacuole

A type of vacuole in plant cells that helps keep turgor preassure

Mitochondria

Double membrane bound organelle with an outer membrane and an inner crista; participates in cellular respiration and ATP production

Oxidative Phosphorylation

The process through which mitochondria produces ATP

Peroxisomes

Membrane bound organelles that break down acids

Endomembrane system

A collection of membrane bound organelles in eukaryotic cells that work together to modify, package, and transport proteins/lipids

Rough and Smooth ER, Golgi, and Vesicles

What organelles are part of the endomembrane system?

A, C, E, B, D

Put the following sequence of Endomembrane functions in order:

A) Protein Synthesis: Ribosomes on the rough ER synthesize proteins.

B) Processing in the Golgi: Proteins are further modified and sorted.

C) Folding and Modification: Newly synthesized proteins undergo initial modifications in the ER.

D) Vesicle Transport: Processed proteins are packaged into new vesicles for transport to their final destinations.

E) Vesicle Formation: Vesicles bud off from the ER carrying these proteins to the Golgi.

Centrosome

Organelle composed of two centrioles arranged perpendicularly; Organizes microtubules during cell division (found in animal cells)

Centrioles

Pair of cylindrical structures within the centrosomes; organize the mitotic spindle (found in animal cells)

Lysosomes

Membrane bound organelles that recycle and clean cellular waste, macromolecules, and pectin (found in animal cells); digest damaged organelles and engulfed pathogens, such as bacteria, within vesicles

Cell wall

Cellular structure made up of cellulose, hemicellulose, and pectin; provides structural support and protection against stress (found in plant cells)

Chloroplasts

Double membrane bound organelles containing chlorophyll; site of photosynthesis (found in plant cells)

Cytoskeleton

A structure of protein fibers within the cytoplasm that provides structural support, facilitates cell movement, and maintains cell shape

Microtubules

Hollow tubes made of tubulin that provide rigidity and serve as tracks for organelle movement

Intermediate filaments

Fibrous proteins that provide mechanical strength and support to the cell

Microfilaments

Thin solid rods made of actin proteins involved in cell movement and that support cell shape (ex. muscles)

Flagella

Long whiplike structures that propel entire cells

ex. Sperm or algae movement

Cilia

Hairlike projections that help propel fluids across cell surfaces (ex. trachea) or help with the reception of signals (ex. sensory olfactory neurons)

Extracellular Matrix (ECM)

A complex network of proteins and carbohydrates that surround cells in tissues (ex. collagen); provide structure, regulate function, and aid in cell signalling

Cell adhesion, cell migration, and cell differentiation

List 3 examples of activities of the extracellular matrix

Cell Junctions

Specialized structures that facilitate communication and adhesion between adjacent cell or between cells and the ECM

Desmosomes

A type of cell junction

Anchors cells together using intermediate filaments, especially in tissues subject to mechanical stress (ex. skin)

Gap junctions

A type of cell junction

Channels that allow direct communication and the exchange of small particles between adjacent cells to coordinate cell activities (ex. cardiac muscle contraction)

Tight junctions

A type of cell junction

Forms a continuous barrier between cells sealing off the intercellular space to maintain tissue integrity and reliable transport

Plasmodesmata

A type of cell junction in plant cells

Cytoplasmic channels that traverse the cells walls of plant cells, connecting the cytoplasm of adjacent cells

Desmosome

What cell junction is this?

Gap junction

What cell junction is this?

Tight junction

What cell junction is this?

Plasmodesmata

What cell junction is this?

Fluid mosaic model

Model proposed by S.G. Singer and Garth Nicolson in 1972; depicts the plasma membrane as a mosaic of components that can move laterally within the membrane

Phospholipids, proteins, cholesterol, and charbohydrates

What are the main 4 components of the plasma membrane?

Phospholipids

Provide the structural component forming a lipid bilayer in the plasma membrane

Head

Part of a phospholipid that is hydrophilic; made up of a phosphate group attached to a glycerol molecule; oriented towards the outside of the membrane

Tail

Part of a phospholipid that is hydrophobic; consists of two saturated or unsaturated fatty acid chains; oriented towards the inside of the membrane

Saturation of phospholipid tails and presence of cholesterol

The fluidity of the plasma membrane depends on ________ and __________

Integral proteins

proteins that span the lipid bilayer and function in transport and signaling.

Peripheral proteins

proteins that are attached to the surface of the lipid bilayer and provide structural support and participate in signaling.

Channel and Transport proteins

List two types of integral proteins

In the outer surface

Where are carbohydrates found in the phospholipid bilayer?

Cell Recognition, Immune Response, and Cell-Cell communication

List the three functions of carbohydrates in the plasma membrane

Inside the phospholipid bilayer

Where is Cholesterol found in the cell membrane?

Regulates the fluidity of the cell membrane

Why is cholesterol important

Receptors

Integral proteins that bind specific molecules (ligands) such as hormones, neurotransmitters, or antigens and trigger cellular responses by initiating signal transduction pathways

Recognition sites

Carbohydrate chains on glycoprotiens and glycolipids that allow cells to recognize and adhere to each other

Viruses

_____ exploit specific glycoprotiens and receptors on host cell membranes for attachment and entry

Viral evolution

Rapid changes in surface markers (antigens) that allow viruses to evade immune detection and adapt to host defenses

Diffusion

Passive transport where substances move from high to low concentration

Passive transport

Molecule transport that does not require energy

Concentration gradient, Molecular size, Temperature, Solvent density

List the 4 factors that affect diffusion

Greater

Greater or less?

The ____ the difference in the concentration of two solutions the faster diffusion

Smaller

Bigger or smaller?

The ____ the molecules the faster the rate of diffusion

Higher

Higher or Lower?

The ____ the temp the faster the rate of diffusion

low

High or low?

Solvents with ___ densities dissolve faster

Facilitated diffusion/transport

Diffusion that utilizes transport proteins (channels or carriers) to move substances too large to diffuse through the membrane; does not use energy and moves with the concentration gradient

Osmosis

Diffusion specific to water molecules; moves water from low solute concentration to high solute concentration

Hypotonic

What type of solution is the cell in?

Water enters the cell because its concentration of solutes is higher than that of the solution causing lysis

Hypotonic

The solution or cell in reference has less solutes than that it is being compared to

Hypertonic

The solution or cell in reference has more solutes than that it is being compared to