AP BIO Test 2

why are there do many folds in the mitochondria?

it allows more surface are --> allows more ATP to be made

what is the primary purpose of a hydrolytic enzyme

- Intracellular digestion - Recycling of organic materials - Programed cell death

Smooth Endoplasmic Reticulum

- Structure: does NOT have ribosomes attached - Function: detoxification for cells and lipid synthesis - synthesize lipids, phospholipids as in plasma membranes and steroids

what is the benefit of elephants ears and how does it relate to thermal energy

As organisms increase in size their surface area to volume ratio decreases affecting properties like the rate of heat exchange with the environment. The flattened shape of their ear allows the elephant to dissipate more thermal energy as blood flows closer to the surface.

how does the structure of the sub cellular components help in its function?

It allows the subcellular components to have different functions which all help the cell survive

Describe the best cell that maximizes surface area to volume ratio

The best cell to maximize the surface area to volume ratio has many folds to increase the surface area.

Explain the benefit of membrane folding in the small intestine of animals and humans

The outer lining of the small intestine is highly folded and contains cilli. The surface area of these villi have additional microscopic projections called microvilli which further increase the surface area available for absorption of nutrients.

grana

the stacks of thylakoids embedded in the stroma of a chloroplast.

What is the function and structure of the stoma?

- Fluid between the inner chloroplast membrane and outside thylakoids - the carbon fixation (Calvin Benson cycle ) reactions occur here

What is the structure of the Thylakoid?

- Highly folded membrane compartments that are organized by stacks called grana - membranes contain chlorophyll pigment that compose the photosystems and electron transport proteins can be found between photosystems, embedded in thylakoid membrane - Light dependent reactions occur here - Folding of internal membranes increases the efficiency of these reactions

Vacuole

- Structure: membrane bound sacs found in eukaryotic cells - Function: play a variety of roles ranging from storage of water and other macromolecules to the release of waste form a cell - Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

How does SA to V ratio limit cell size

- as a cell increases, its volume increases much faster then its surface are - if a cell doubles the cell would require 8X more nutrients and have 8X more waste to get rid of

Ribosomes

- consist of two subunits that are NOT membrane enclosed - made up of mRNA and proteins - synthesizes protein according to mRNA sequences that are encoded from the genome of the cell

volume

- determines the amount of metabolism in the cytoplasm - metabolism will require the import of precursors - metabolism will result in the export of secretions - and the export of excretory products

surface area

- will determine the exchange of materials between the cell and its environment - bigger cells will metabolize more - but they will need more surface to support that metabolism - the sites of metabolism in bigger cells will be further from the surface of the cell

what factors control or limit cell size

1. diffusion limits size 2. DNA content limits size 3. SA:V limits size

Procaryotic cells

Cells without true nuclei, lacking many other structures found in eucaryotic cells.

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

What 2 sub cellular compounds are necessary in all cells?

Genome and Ribosomes - genetic information that reflects common ancestry of all life

Why are these folds beneficial for the cell and organs?

Membrane folding increased surface area.

Explain the benefit of membrane folding in plants

Root hairs on the surface of plant roots increase the surface area of the root allowing for increased absorption of water and nutrients.

Explain the importance of surface are to volume ratio as it relates to cell size

SA:V ratio affects the ability of a biological system to obtain necessary resources, eliminate waste products, acquire and dissipate thermal energy, and otherwise exchange chemicals and energy with the environment.

What is the effect on cells having a higher SA:V ratio?

Smaller cells typically have a higher surface area to volume ratio and more efficient exchange of materials with the environment

What do smaller cells typically have compared to larger cells?

Smaller cells typically have a higher surface area to volume ratio and more efficient exchange of materials with the environment.

Where is the electron transport chain located in a mitochondria?

The inner mitochondrial membrane

What is turgor pressure and how does it relate to the pressure of a plant?

Turgor pressure is an internal cellular force, usually caused by water pushing up against the plasma membrane and cell wall → it would increase trigger pressure and increase wilting

smaller cells

allows the cell to be more efficient

How does DNA content limit size

cells usually contain only one nucleus - DNA is found in the nucleus - DNA makes RNA - RNA will travel through the cytoplasm to the ribosomes - RNA assists the ribosomes in making protein - DNA is responsible for the whole process If the cell was very large, there would not be enough DNA to support the cell

what materials does the vacuole hold?

enzymes, waste, food, and water.

Where does the Krebs cycle occur?

mitochondrial matrix

why does it make sense for animal cells to have more lysosomes than a plant?

Animals have more lysosomes because we actually get energy from consuming food and digestion when plants only get energy from the sun

how does the SA to V ratio affect the Arte of heat exchange in the environment

As an organism increases in size, their surface area to volume ratio decreases making it harder to release heat energy and adaptations may improve an organism's efficient in doing so.

What are some examples of structural modification of cells that increase surface area

As cell volume increases or a cell becomes specialized for transport across its surface, structural modifications such as membrane folds are necessary to adequately exchange molecules from or into the environment.

how are specialized structures and strategies used by cells and organisms for efficient exchange of molecules with the environment

They help regulate the cell like stomatal openings on the surface of a leaf.

Chloroplast

- Structure: found in eukaryotic cells such as photosynthetic algae and plants - Function: double outer membranes; specializes for capturing energy from the sun and producing sugar for organisms - organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

Mitochondria

- Structure: has a double membrane (outer --> smooth, inner --> cristae) - Function: production of ATP energy that eukaryotic cells can use for cell work - Powerhouse of the cell, organelle that is the site of ATP (energy) production

Rough Endoplasmic Reticulum

- Structure: has ribosomes attached to its membrane times within cytoplasm of eukaryotic cells - Function: packages the newly synthesized proteins made by attached ribosomes for possible export from cells - protein molecules

Lysosome

- Structure: membrane enclosed sacs found in some eukaryotic cells that contain hydrolytic enzymes - Function: hydrolytic enzymes can be used to digest a variety of materials such as damages cell parts or macromolecules - cell organelle filled with enzymes needed to break down certain materials in the cell

Golgi apparatus

- Structure: series of flattened membrane bound sacs found in eukaryotic cells - Function: involved in correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking - A system of membranes that modifies and packages proteins for export by the cell

what is the purpose of a plants stomata

- The stomata helps the plant obtain molecules from and release molecules into the surrounding environment. - When the stomata are open CO2 can enter the leaf and O2 and H2O can be released into the atmosphere.

When do cells divide

- all organisms grow and change - cells are constantly growing , dividing, an ddying - some cells divide more than others * heart and nerve cells rarely divide * asking cells are constantly dividing * growth is related to specificity and activity * if cell growth is uncontrolled --> leads to cancer

Why do larger cells have difficulty with demands if internal resources and waste removal?

As the cell increased in volume the relative surface area decreases making it difficult for larger cells to meet the demand for internal resoures and remove waste sufficiently. (Restricts cell size and shape)

Cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.