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Flashcards in Pre-reqs eukaryote notes Deck (25):
1

A phospholipid bilayer that encloses the entire cell.

plasma membrane

2

Defines the boundary of the cell; separates cell from the outside environment)
Regulates what can enter/exit the cell

plasma membrane

3

composition of plasma membrane?

Carbohydrates (oligosaccharides) - on the outer surface of cell
Lipids
Phospholipids & glycolipids - form the membrane’s bilayer
Sterols - fit into the bilayer between the other lipids
Proteins - Dispersed throughout the bilayer

4

Nucleus?

Function: (1) acts as the cell’s control center; (2) houses the DNA & the nucleolus.

5

Double membrane layer
2 FUNCTIONS:
Surrounds nucleus, separates it from the rest of the cell.
Contains nuclear pores: protein-lined holes that regulate what enters and exits the nucleus

nuclear envelope

6

Nucleolus?

Dark spot found inside the nucleus; associated with particular regions of the DNA.
Function: produces rRNA (to become part of the ribosome

7

Function: carry out aerobic cellular respiration (break down glucose to make ATP).

mitochondria

8

mitochondria structure?

Structure: surrounded by a double layer of membranes.
Cristae - folded inner membranes; where the electron transport chain is located
Matrix - inner space where the citric acid cycle (Krebs cycle) occurs

9

chloroplasts?

Function: where photosynthesis occurs.
Contain Chlorophyll (the molecule that captures energy from light), which gives them the green color.

10

structure of chloroplasts?

Structure: surrounded by a double layer of membranes.
Thykaloids - Stacks of membranes inside the chloroplast; where the light reactions of photosynthesis take place.
Stroma - space outside thylakoids where the dark reactions of photosynthesis (Calvin cycle) take place.

11

Network of interconnected membranes extending throughout the cytosol.

endoplasmic reticulum

12

ROUGH ER structure and function?

Continuous with nuclear envelope & covered with ribosomes.
Function: modifies proteins during translation.

13

SMOOTH ER structure and function?

Not continuous with nuclear envelope; not covered with ribosomes; not involved in protein modification.
Function: synthesize lipids; detoxify & deactivate certain harmful substances.

14

golgi complex structure and function?

stack of flat membrane-enclosed sacs that can resemble a stack of pancakes.
Functions:
Modify, process & package proteins, after translation is complete and they have left the ER.
Golgi modifications help direct proteins to their correct destinations.

15

Lysosomes?

not found in plants
Function: digest food molecules and break down damaged components of the cell.

16

lysosomes contain these?

hydrolases, which break down all sorts of different molecules by hydrolysis.

17

peroxisomes?

Functions vary depending on cell type.
Animals - break down various compounds such as long-chain fatty acids by oxidation.
Plants - specialized peroxisomes play other roles.
Reactions inside generate harmful peroxides such as H202
A peroxisome enzyme called catalase converts H202 to water in order to protect the cell.

18

Vacuoles in Animals, yeast:

temporary storage or transport outside the endomembrane system.

19

Vacuoles in certain protists?

some vacuoles are formed during phagocytosis to hold the food particles; others are specialized to pump water out of the cell.

20

Vacuoles in plants?

large central vacuole maintains turgor pressure; also plays roles in intracellular digestion & storage of nutrients or wastes

21

what are these?

In eukaryotes, some are attached to the rER & others float in cytoplasm. Still others are located inside mitochondria and chloroplasts.

22

cytoskeleton

A network of protein fibers extending throughout the cell.
3 different structural elements made of protein.
Microfilaments (smallest)
Microtubules (largest)
Intermediate filaments (mid-sized)

23

functions of cytskeleton

Establish, maintain cell shape.
Movement of cell; Movement & positioning of organelles.
Roles in mitosis, meiosis and cytokinesis

24

Outside the cell membrane, cells have structures used for cell-cell communication.
This is a fibrous network of proteins & polysaccharides produced by the cell and deposited outside the cell membrane.
It gives physical support to the cell.
Participates in regulating certain processes inside the cell.
Its crucial for many types of cell-cell communication.

extracellular matrix

25

Bacterial cells, plant cells, fungus cells, some protist cells & some archaea cells have a CELL WALL.
Rigid structure outside cell membrane that protects & supports the cell; helps maintain turgor pressure; prevents cells from collapsing due to osmotic pressure.

cell walls