Cell Structure (Chapter 4)

Question 1

prokaryotic cells

Answer 1

lack a membrane-bound nucleus. genetic material is present in the nucleoid.
bacteria and archaea

Question 2

prokaryotic cell characteristics

Answer 2

genetic material in the nucleoid
cytoplasm
plasma membrane
cell wall
ribosomes
no membrane-bound organelles

Question 3

surface area-to-volume ratio

Answer 3

as cell size increases, the volume icreases 10x faster than the surface area

Question 4

eukaryotic cells

Answer 4

possess a membrane bound nucleus

compartmentalism many cellular functions within organelles

Question 5

nucleus

Answer 5

for ribosome synthesis
DNA that is organized with proteins to form chromatin
surrounded by a nuclear envelope composed of 2 phospholipid bilayers which is continuous with the endoplasmic reticulum
nuclear pores allow substance to enter and exit nucleus

Question 6

ribosomes

Answer 6

made up of a large subunit (top) and small subunit (bottom)
sure of protein synthesis in the cell
composed of ribosomal RNA and proteins
found within the cytoskeleton of the cytoplasm and attached to internal membranes

Question 7

mitochondria

Answer 7

transfers the energy within macromolecules to ATP

Question 8

peroxisomes

Answer 8

break down fatty and amino acids
detoxify poisons like alcohol
break doe H2O2 into oxygen and water
convert stored fats into sugars

Question 9

vesicles and vacuoles

Answer 9

function in storage and transport 
vesicles fuse with the membrane and vacuoles do not

Question 10

centrosome

Answer 10

organelle where all microtubules originate
two centrioles that lie at right angles to each other
each centriole is a cylinder made up of nine triplets of microtubules

Question 11

lysosomes

Answer 11

membrane bound vesicles obtaining digestive enzymes to break down macromolecules
destroy cells or foreign matter that the cell has engulfed by phagocytosis

Question 12

cell wall

Answer 12

surrounds cell

composed of cellulose or chitin

Question 13

chloroplasts

Answer 13

present in plant cells
contains chlorophyll
the light harvesting reactions take place in the thyakoid membrane

Question 14

the endomembrane system and proteins

Answer 14

series of membranes throughout the cytoplasm (can be rough or smooth)
divides cell into compartments

Question 15

cytoskeleton

Answer 15

actin filaments- aka microfilaments. responsible for cellular contractions, crawling, and pinching. smallest structures.
microtubules- largest cytoskeletal structure. provides organizations for moving materials with the cell. component of flagella and cilia
intermediate filaments- provide structural stability

Question 16

extracellular matrix

Answer 16

consists of a network of proteins and carbohydrates outside the cell
composed of glycoproteins and fibrous proteins such as collagen
may be connected to the cytoplasm via integrin proteins present in the plasma membrane

Question 17

intercellular junctions

Answer 17

plasmodesmata- channel that pass between cell walls of adjacent plant cells
tight junction- a watertight seal between two adjacent animal cells
gap junction- channels between adjacent animal cells
desmosomes- maintain the cells in a sheet-like formation