unit 4 cellular structure and function

Question 1

What are prokaryotes and what are some examples of them?

Answer 1

Cells that lack a nucleus or membrane-bound organelles. They contain cytoplasm and ribosomes, but instead of having a nucleus, they have a nucleoid region that contains DNA.
examples: Some forms of bacteria as well as archaea,which are microorganisms that live in extreme environments (e.g., high altitudes, deep oceans, or extreme heat).

Question 2

What are eukaryotes and what are some examples?

Answer 2

they are larger and more complex, containing a nucleus and various organelles like mitochondria, chloroplasts, and more. All plants, animals, fungi, and protists are eukaryotic.

Question 3

What is the endosymbiotic cell theory?

Answer 3

some structures in the modern eukaryotic cell developed from early prokaryotes, such as mitochondria, and in plants, chloroplasts

Question 4

What is the function of the nucleus?

Answer 4

Stores the cell’s genetic material (DNA) and controls its activities.

Question 5

What is the function and origin of the mitochondria?

Answer 5

Known as the “powerhouses” of the cell, they generate energy in the form of ATP (Cellular respiration)
descendent of micro bacteria that were aerobic heterotrophic prokaryotes

Question 6

What is the function of the golgi bodies/apparatus?

Answer 6

Receive proteins from the rough endoplasmic reticulum, and other newly formed hormones and lipids from the smooth endoplasmic reticulum, and distribute them to toher parts of the cell. They also release materials outside the cell.

Question 7

What is the function of ribosomes:

Answer 7

: Produce and release proteins in the rough endoplasmic reticulum and the cytoplasm.

Question 8

What is the function of the rough endoplasmic reticulum?

Answer 8

ssembles and processes proteins. It is covered with ribosomes that assemble amino acids, and the folds of the ER modify and fold these proteins into the correct structure. These proteins are then sent to the Golgi bodies.

Question 9

What is the function of the smooth endoplasmic reticulum?

Answer 9

Processes lipids, distributes hormones, and breaks down toxins. Doesn’t contain ribosomes.

Question 10

What are the differences between the rough and smooth endoplasmic reituclum

Answer 10

-the rough endoplasmic reticulum contains ribosomes nad processes proteins.
-the smooth endoplasmic reticulum processes lipids, distributes hormones, and breaks down toxins.

Question 11

What is the function of the nucleolus

Answer 11

The nucleolus A small object in the middle of the nucleus that makes ribosomes

Question 12

What is the function of the cell/plasma membrane?

Answer 12

Encircles the cytoplasm and allows beneficial substances to enter the cell, controls secretion of substances by the cell, and prevents harmful substances from entering the cell.

Question 13

What is the function of vacuoles

Answer 13

large water-filled sacs in the cytoplasm of the cell that serve as storage vessels for waste byproducts and materials needed by the cell.
- plant cells have one large vacuole called the central vacuole, and animal cells have many small vacuoles

Question 14

What is cytoplasm and what is it’s function

Answer 14

the constantly moving fluid between the cell membrane and the nucleus. It’s constant motion allows the organelles to move freely throughout the cell.

Question 14

What is the function of the nucleus

Answer 14

Stores the cell’s genetic material (DNA) and controls its activities.

Question 15

Peroxisomes

Answer 15

Small, membrane-bound organelles that help the cell break down harmful substances. They contain enzymes that break down fatty acids and detoxify harmful molecules.

Question 16

microfilaments:

Answer 16

Structures made up of protein that are part of the cytoskeleton and help the cell maintain its shape, move, and divide during cell reproduction

Question 17

Microtubules

Answer 17

Hollow tubes made up of protein fibers within the cytoskelton that guide the movement of vesicles and organelles

Question 18

What organelles are exclusively in plant cells?

Answer 18

plastids/chloroplasts, central vacuole, cell wall, plasmodesmata

Question 19

What is the cell wall and what is its function?

Answer 19

A rigid, semi-permeable membrane of nonliving material (cellulose) that surrounds the plant cell. Helps protect and support the cell.

Question 20

What organelles are exclusively in animal cells?

Answer 20

centrioles and locomotion organelles including flagellum and cilia

Question 21

What are centrioles and what is their function?i

Answer 21

(exclusively in animal cells) Small structures that are made of microtubules (protein fibers) and play a key role in cell division

Question 22

What are locomotion organelles and why do only animal cells have them

Answer 22

Locomotion organelles are structures that help cells move or interact with their environment, such as cilia, flagella, and pseudopodia
- in animal cells, locomotion organelles are used in reproduction (e.g) sperm and to fight off bacteria
- Only animal cells have organelles for many reasons:
1. plants are stationary organisms.
2.the cell wall prevents invasive bacteria from entering the cell, so the cell doesn’t necessarily have to attack other cells as frequently. Another reason is that plants rely on structural adaptations like roots, stems, and leaves to grow toward light, absorb water, and transport nutrients. These allow it to gain resources while remaining stationary. Lastly, plants also depend on external factors like wind, water, or animals for processes like pollination and seed dispersal, so cell movement isn’t necessary for reproduction.

Question 23

What are archaea

Answer 23

microorganisms that thrive in extreme environemnts (e.g bottom of the ocean, high altitueds, extreme temperatures)

Question 24

What is the endosymbiotic cell theory?

Answer 24

some structures in the modern eukaryotic cell developed from early prokaryotes, such as mitochondria, and in plants, chloroplasts

Question 25

How did the modern eukaryotic cell form (endosymbiotic cell theory)

Answer 25

As cells evolved, ancestral prokaryotes (containing just DNA and cytoplasm, the nucleus was formed later) engulfed heterotrophic prokaryotes ( mitochondria) and autotrophic, photosynthetic prokaryotes (chloroplasts.) which formed a symbiotic relationship.

Question 26

Why was a symbiotic relationship formed between the cyanobacteria (now chloroplasts) and the mitochondria (aerobic, heterotrophic eukaryotes) in the ancestral eukaryotic plant cell?

Answer 26

his is because the mitochondria perform cellular respiration to break down the glucose produced by the chloroplasts in photosynthesis. These two systems provide energy to each other, and by breaking down the glucose produced by photosynthesis in the chloroplasts into ATP, power cellular processes.

Question 27

Why was a symbiotic relationship formed in the heterotrophic ancestral eukaryote?

Answer 27

• The cell would consume energy, and the mitochondria would break it down into ATP, which allowed it to break bonds/ release energy more efficiently.

Question 28

What is the cell theory?

Answer 28

All organisms are composed of one or more cells.
The cell is the most basic unit of life.
All cells come from other pre-existing cells.

Question 29

What is cell differentiation and what are some examples?

Answer 29

the acquisition of a cell’s specific structural and functional features after creation
Examples:
-The shape of red blood cells,
-the length of neural cells(neurons) and skeletal muscle cells
- the locomotive character of sperm cells,

Question 30

what are lysomes and what is their function?

Answer 30

small organelles found in the cytoplasm that contain digestive enzymes to break down complex molecules taken in by cells, such as lipids, carbohydrates, and proteins.

Question 31

What is the cytoskeleton and what is its function?

Answer 31

The network of protein filaments that support the structure of the cell. ome of their components also contribute to internal transport and cell movement.
- made up of the microfilaments and microtubules

Question 32

what are the two major parts of a eukaryotic cell?

Answer 32

nucleus and cytoplasm

Question 33

what is the defining feature of a eukaryotic cell?

Answer 33

the presence of a nucleuis as opposex to a nucleoid region.

Question 34

What is passive transport and what are some examples of it?

Answer 34

Substances diffuse spontaneously down the concentration gradients crossing a membrane with no expenditure of energy by the cell
- osmosis
simple diffusion
-facilitated diffusion

Question 35

what is simple diffusion and what is it an example of?

Answer 35

the mvoement of small, non-polar (hydrophobic) and small, uncharged nonpolar mmolecules through the phospholipid bilayer
-passive transport, because it doesn’t require ATP

Question 36

What is active transport and what are some examples of it?

Answer 36

-Active transport is the movement of moelcules through proteins that act as pumps, across a membrane against their concentration gradients. Energy for this work is usually supplied by ATP.
-exocytosis and endocytosis (phagocytosis is a form of endocytosis)

Question 37

What is facilitated diffusion and what is it an example of?

Answer 37

Facilitated diffusion is the movemnt of large, uncharged polar molecules (e.g. glucose) and ions into the cell through integrated protein channels in the cell membrane. This allows molecules not normally would not be able to penetrate the membrane to enter the cell. it is an example of passive transport because it doesn’t require energy.

Question 38

How does exocytosis work and what type of transport is it?

Answer 38

the cell secretes macromolecules by the fusion of vesicles with the plasma membrane.
-active transport

Question 39

What is endocytosis and how does it work+examples?

Answer 39

The cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane
Examples: Phagocytosis(“Cellular eating”), Pinocytosis (“Cellular Drinking”), and Receptor Mediated Endocytosis

Question 40

what is the function of vesicles?

Answer 40

vesicles are small, membrane-bound sacs within cells that transport, store, or digest substances. They can move molecules between organelles, or to and from the cell membrane (endocytosis and exocytosis)

Question 41

what two features do all cells have?

Answer 41

-DNA and a cell membrane

Question 42

What are the differences between the golgi apparatus and the endoplasmic reticulum?

Answer 42

The endoplasmic reticulum assembles and processes proteins and lipids which are later sent to the golgi apparatus for distribution to the rest of the cell.

Question 43

What is the structure of the endoplasmic reticulum and what is its purpose?

Answer 43

Network of membranous tubules and sacs, which allows the proteins and lipids to be easily moved through the cell to the golgi apparatus.

Question 44

What is biuret’s solution used to test for? What color indicates a positive test? What functional group reacts with the reagant and produces this qualitative change?

Answer 44

protein
-the biurets solution is originally blue and changes to violet/lavender
-amino acids and carboxyl groups react with the reagent to produce this qualitative change

Question 45

What solution tests for polysaccharides/starch? What color indicates a positive test?

Answer 45

-lugol’s, yellow/brown

Question 46

What solution test for monosaccharides/glucose? What color indicates a positive test?

Answer 46

it changes from blue to orange

Question 47

what is turgor pressure?

Answer 47

The force directed against the cell wall in a plant cell from the influx of water in hypotonic extracellular fluid