Unit 2 study guide bio

What characteristics do all cells share?

- plasma membranes

- chromosomes (DNA)

- cytoplasma

- Ribosomes (for protein synthesis)

What are the key points of the cell theory?

- All organisms are made of cells

- most basic unit of life

- All cells decend form earlier cells

How do eukaryotic and prokaryotic cells compare in size to each other?

Eukaryotic cells are larger than Prokaryotic cells

Organelle size

smaller and cells but larger than macromolecules

Biological macromolecules size

(like proteins/DNA) smaller than organelles

Viruses size

20-800 nm, smaller than prokaryotic cells

Prokaryotes make up which domain(s) of life?

Bacteria and Archaea

What structure(s) enclose prokaryotic cells ?

- plasma membrane

- cell wall (most)

capsule ( some for protein )

Eukaryotes make up which domain(s) of life?

Eukarya

Which eukaryotes have cell walls? Which do not? What are the cell walls made of?

plants: cellulose

fungi: Chitin

Animal cells: no cell wall

What is the function of the nucleus?

Stores DNA and controls the cells activity, like growth/ metabolism/ reproduction

What is chromatin?

DNA + proteins ( uncolied forming nucleus)

What is a chromosomes?

Condensed chromatin visible during cell division (2 complete sets of 23) ( total =46)

How do items get into and out of the nucleus?

through the nuclear pores that covered the surface of the nuclear envelope

What happens at the nucleolus? What materials are needed at the nucleolus to carry out the process ?

Function: make ribosomes

Needed: DNA( instructions) and proteins (from cytoplam)

What organelles/structures make up the endomembrane system ?

- nuclear envelope

- cell membrane

- Endoplasmic Reticulum

- Golgi apparatus

- Lysosomes

- Vesicles and Vacoles

What are the two types of ER ?

Smooth ER and Rough ER

How do we tell the difference between the two ERs, structurally?

Smooth ER: no Ribosomes, makes lipids, detoxification ( enzymes help)

Rough ER: has ribosomes, synthezies and folds proteins

What structure does a cell use to synthesize proteins?

Ribosomes

What are the possible destinations for proteins made on bond ribosomes

exported from the cell/ incerted in to membrane/ sent to the lysosome or Golgi

What does the Golgi apparatus look like?

a stack of pita bread

What happens in the Golgi apparatus?

proteins and lipids are modified, stored, then tagged with a "shipping" label before sent off.

How do things travel between the ER and Golgi?

transport vesicles

What are vacuoles?

large vesicles derived from the ER and Golgi apparatus

What are some different types ( and functions) of vacuoles?

Food Vacuoles: stores or digest food by, phagocytosis

Central Vacuoles: in plant cells, store water

Contractile Vacuoles: pump out: maintain solute concentration

What is the main function of a mitochondrion? What two compounds does this organelle need to carry out this

Function: Cellular respiration makes ATP

Need : Glucose and Oxygen

What are the structural parts of the mitochondria? What is the advantage of having additional cristae?

- Outer membrane

- inner membrane (folded into cristae)

- matrix (inside fluid)

advantage: increasing the surface area for ATP production

What is the main function of Chloroplast?

Function: photosynthesis ( makes sugar from sunlight)

What type of organelle is a chloroplast ?

energy- converting ( plasrid )

What are the structural parts of the Choloplasts?

Inner and Outer Membrane

flat sacs: thykoids stacked in grana: fluid around stacks is stroma

What types of Eukaryotes contain Chloroplasts

plants and algae

What is a peroxisome?

Break down fatty acids for energy/ break down toxins, detoxify hydrogen peroxide using catalse

What are the functions of the Eukaryotic cytoskeleton?

- mechanical support to maintain cell shape

- anachorage for organelles (move them)

- Cell mortality (division/movement)

What are the three components of the cytoskeleton ?

- micro tubules (thickest)

- micro filaments (thinnest)

- intermediate filament

What motor proteins are associated with each type of cytoskeletal fiber?

microbubules: dynein motor protein

microfilment: myosin motor proteins

Why do we need Cytoskeletal motor proteins?

to move vesicles, organelles, and the entire cell.

What are cillia?

Short, hair-like structures (move substance/ the cell)

What are flagella?

long, whip-like tail ( move the cell)

What are cilia and flagella used for?

movement

What cytoskeletal component makes up cilia and flagella?

Microtubules

How is the cytoskeletal structure within cilia and flagella?

Microtubules are arranged in the 9+2 pattern

What is a pseudopod?

a temporary extension of cytoplasm used for movement and feeding in some cells (like amobas)

What cytoskeletal component makes up a pseudopod?

microfilaments: they extend and retract to push the cell's membrane forward

What are the three types and functions of cell-cell junctions in animal cells?

tight: seals to prevent leakage (skin )

Gap: channels that allow small molecules to pass and communicate

Desmosomes: like rivets and fasten cells tightly together

Why don't we talk about cell-cell junctions in eukaryotes like yeast, Amoeba, Euglena, orParamecium?

because they are unicellular not multi celluar.

Cell Junctions are used to connect cells within the tissue of multicellular organisms

What is the main type of cell-cell junction in a plant cell? What is its function?

plasmodesmata: perforate the cell wall and allow passage of small molecules (similar to Gap Junctions and animal cells)

What components make up a membrane (like the plasma membrane) in a cell?

phospholipids : main structure

protein: transport and signaling

cholesterol: fluidity

carbohydrate: cell recognition

How are these components arranged in the membrane?

Arrangement : phospholipid bilayer with hydrophilic acids and hydrophobic sells inward

What is the fluid-mosaic model?

The membrane is the mosaic of protein molecules bobbing in a fluid bilayer of phospholipids.

What are some functions that proteins play in membranes?

Transport using ATP:

Enzyme activity:

Signal transduction:

Cell-to-cell recognition:

intercular joining.

Attachment to the cytoskeleton and extracellular matrix

What is the difference between integral and peripheral membrane proteins?

integral - span the membrane (proteins that extend entirely across the cell's lipid bilaye)

Peripheral - attached to the surface of the membrane

What is passive transport?

no energy is required in diffusion down is concentration

What is active transport?

requires energy ATP (high to low concentration)

What is diffusion?

tendency for molecules to spread out evenly into available space

What is osmosis?

diffusion of water across a selectively permeable membrane

What factors affect the rate of diffusion?

temperature, concentration gradient, surface areas, molecule size and distance

What happens to the movement of a solute (like glucose molecules or salt ions) when a cell is placed in a hypertonic solution? in a hypotonic solution? in an isotonic solution?

hypertonic solution: moves into cell

hypotonic solution: moves out of the cell

isotonic solution: no movements stay the same

What happens to the movement of water when a cell is placed in a hypertonic solution? in a hypotonic solution? in an isotonic solution?

hypertonic solution: water moves out (cell shrink)

hypotonic solution: water moves in (cell swells)

isotonic solution: no movement

What is crenation?

animal cell shrivels up in hypertonic solution

What is lysis?

animal cells burst in hypotonic solution

What is turgor pressure?

Pressure of water pushes against the cell wall in plants (Good)

What happens to turgor pressure when you place a plant cell in a hypertonic solution? a hypotonic solution? An isotonic solution? What is plasmolysis?

hypertonic solution: loses water, called plasmolysis (membrane pulls away from the wall

Hypotonic solution: gain water.. strong turgor pressure

isotonic solution: no pressure change.

What happens at equilibrium?

molecules still move but no net change in concentration across membrane

What is facilitated diffusion?

passive movement through channels /carrier proteins for molecules that cannot cross lipids bilayer easily

How do channel proteins differ from carrier proteins?

channel- proteins open pores

carrier proteins - change shape to move molecules

How do cells accomplish active transport?

using a transport protein (pump) poured by ATP

Why is active transport important?

Active transport allows molecules to move across cell membranes and epithelial membranes against a concentration gradient.

sodium-potassium pump

A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell. Moves 3 Na+ out and 2 K+ in.

What is exocytosis?

Fuses with plasma membrane & releases contents outside of the cell (exo = exit)

What is Endocytosis?

process by which the cell takes in materials that are too large to pass through (import)

What is Phagocytosis?

Cell eating

What is pinocytosis?

Cell drinking

What is receptor-mediated endocytosis?

specific molecules are taken in after they bind to a receptor