chap 4&5

Question 1

Name the major organelles of the Eukaryotic cell

Answer 1

nucleus, rough endoplasmic reticulum, smooth endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, mitochondria, and chloroplasts

Question 2

command center of cell and contains genetic material (DNA)

Answer 2

nucleus

Question 3

membranes studded with ribosomes and synthesize proteins

Answer 3

rough endoplasmic reticulum

Question 4

membranes NOT studded with ribosomes and synthesize lipids

Answer 4

smooth endoplasmic reticulum

Question 5

stack of flattened saccule (looks like pancakes for pita bread) which receive vesicles from rough ER (contain proteins) and form smooth ER (contain lipids), alters the contents of the vesicles (proteins and lipids) as they move through the saccule, forms vesicles filled with the altered proteins or lipids that exit the Golgi apparatus, vesicles can fuse with the plasma membrane and secrete their contents (exocytosis) or stay in the cell

Answer 5

Golgi apparatus

Question 6

small vesicles exiting the Golgi apparatus that stay in the cell and filled with specialized proteins (originating from rough ER) called digestive enzymes that are used to recycle cellular materials or digest substances brought into the cell

Answer 6

lysosomes

Question 7

membrane-bound vesicles whose proteins are synthesized by FREE ribosomes (those floating around in the cytoplasm and not bound to rough ER), have enzymes which catalyze chemical reactions that produce hydrogen peroxide which is toxic to the cell, also have an enzyme (catalase) which breaks down toxic hydrogen peroxide into non-toxic water and oxygen, and found in both plant and animal cells

Answer 7

peroxisomes

Question 8

membrane-bound sacs much larger than vesicles, store nutrients and wastes, maintain hydrostatic (turgor) pressure, and found primarily in plants

Answer 8

vacuoles

Question 9

break down glucose to produce energy in the form of ATP during cellular respiration, and found in both plants and animals

Answer 9

mitochondria

Question 10

capture solar energy during photosynthesis and use that energy to make glucose and oxygen, and found in plants

Answer 10

chloroplasts

Question 11

How are plant cells different from animal cells?

Answer 11

only plant cells have a cell wall, chloroplasts, and a large central vacuole

Question 12

what is programmed cell death?

Answer 12

Apoptosis

Question 13

when lysosomes are programmed to digest parts of the organism, like a tadpole’s tail during metamorphosis. This gets rid of cells that are no longer needed by the organism

Answer 13

Apoptosis

Question 14

What is Tay-Sachs disease?

Answer 14

it’s a genetic disorder in which the body has missing lysosomal enzyme, this enzyme normally digests fat insulating nerve fibers, and if the enzyme is missing, this results in an accumulation of fatty substances in nerve cells that smothers the brain; babies with Tay-Sachs have decreased mental and physical abilities and usually die ant a young age

Question 15

How does cellular respiration compare to photosynthesis?

Answer 15

cellular respiration- oxidizes (breaks down) glucose to produce carbon dioxide, water, and energy that is stored in the chemical bonds of ATP and it takes place in the mitochondria of plants and animals

photosynthesis- uses solar energy, carbon dioxide, and water to produce glucose and oxygen and it takes place in green plants only

Question 16

What is the cytoskeleton?

Answer 16

protein fibers extending from the cell nucleus to the plasma membrane that are used to maintain cell shape and move organelles within the cell

Question 17

What is the function of the plasma membrane?

Answer 17

regulates the entrance and exit of molecules into and out of the cell

Question 18

Describe the structure of the plasma membrane.

Answer 18

• phospholipid bilayer with associated protein molecules
• fatty acid tails position themselves toward the inside of the membrane–they are hydrophobic; this makes them as far away from water inside and outside the cell that they can be

Question 19

What are three characteristics of the Fluid-Mosaic model of the cell membrane?

Answer 19

1. basic cell membrane is a phospholipid bilayer
2. cell membrane has associated proteins; the integral proteins float around the phospholipid bilayer like icebergs in an ocean, hence the name “fluid-mosaic model”
3. cell membrane has cholesterol which adds stability to the phospholipid bilayer

Question 20

What is the function of the glycocalyx in animal cells? How is it formed?

Answer 20

It gives each cell tis specific identity; helps cells stick to one another

When sugars are added to integral proteins in the phospholipid bilayer

Question 21

What are the different types of integral proteins and their functions?

Answer 21

Channel proteins, carrier proteins, cell recognition proteins, receptor proteins, and enzymatic proteins

Question 22

Allow the passage of molecules through the cell membrane via a tube

Answer 22

Channel proteins

Question 23

Combine with and transport substances into the cell

Answer 23

Carrier proteins

Question 24

Create a unique chemical identification for cells

Answer 24

cell recognition proteins

Question 25

bind with a messenger molecule like a hormone, causing a cellular response

Answer 25

receptor proteins

Question 26

catalyze (speed up) chemical reactions directly

Answer 26

enzymatic proteins

Question 27

The plasma membrane is selectively permeable or semipermeable. What does this mean?

Answer 27

it allows some substances, but not all, to pass through it.

Question 28

How does passive transport of materials across the plasma membrane differ from active transport?

Answer 28

Passive: -doesn't require energy -it follows a concentration gradient from an area of high concentration to an area of low concentration Active: -requires energy in the form of ATP and either a carrier protein or a vesicle -it follows a concentration gradient from an area of low concentration to an area of high concentration

Question 29

Name and describe two types of passive transport

Answer 29

Diffusion: -movement of molecules from an area of high concentration to an area of low concentration Osmosis: -special case of diffusion involving movement of water across a selectively permeable membrane from an area of high concentration to an area of low concentration -water is the solvent and some dissolved substances is the solute

Question 30

Has both liquid or solvent and a dissolved solid or solute

Answer 30

solution

Question 31

Name and describe the three types of solutions involved in osmosis

Answer 31

Isotonic Solution: - solute concentrations are the same on both sides of the cell membrane - there is no net loss or gain of water from the cell Hypotonic Solution: - solute concentrations outside the cell are LOWER than solute concentrations inside the cell - there is a net gain of water on the inside of the cell. This may cause the cell to burst (lysis) Hypertonic Solution: - solute concentrations outside the cell are HIGHER than solute concentration inside the cell - there is a net loss of water on the inside of the cell - this may cause the cell cytoplasm to shrink away from the cell wall of plant cells (plasmolysis) or the entire animal cell to shrink (crenation)

Question 32

Carrier proteins facilitate the passage of substances though the plasma membrane. This transport can be either passive or active. Describe the differences.

Answer 32

Passive: - small molecules that can't get through the plasma membrane on their own combine with a carrier protein and follow a concentration gradient from an area of higher concentration to an area of lower concentration - no energy is required - an example is glucose and amino acid transport Active: - small molecules that can't get through the plasma membrane on their own combine with a carrier protein and move AGAINST the concentration gradient (from an area of low concentration to an area of high concentration) - requires energy in the form of ATP - an example is the sodium-potassium pump

Question 33

Active membrane-assisted transport involves vesicles fusing with the plasma membrane and allowing substances to enter or exit the cell. What are the two major types? Describe them

Answer 33

Exocytosis -vesicles fuse with the plasma membrane and secrete their contents to the OUTSIDE of the cell Endocytosis - cells engulf outside substances into a pouch of plasma membrane that pinches off to form a vesicle inside the cell - there are three types: phagocytosis, pinocytosis, and receptor-mediated - phagocytosis- occurs when large solid material is engulfed - pinocytosis- occurs when liquid or small solid material is engulfed - receptor-mediated- occurs when a pit is coated with special protein receptors binds to specific substances which are then engulfed

Question 34

In animals there are three types of cell surface modifications that help to hold adjacent cells together. Name and describe them

Answer 34

Adhesion Junction: - cytoskeleton filaments run between two cells - commonly found in stomach, heart, and urinary bladder Tight Junction: - plasma membrane proteins attach to each other, forming a zipper-like barrier - commonly found in kidneys so urine stays put Gap Junction: - adjacent plasma membrane channel proteins are joined for communication between cells - commonly found in heart and smooth muscle for ion transportation

Question 35

Plants have one type of cell surface modification. What is it? Describe it.

Answer 35

Plasmodesmata- narrow, membrane-lined channels passing through the cell wall that connects the cytoplasm of two plant cells