✅Basic Cells And Tissue

Question 1

What are basic cell functions?

Answer 1

Obtain nutrients and oxygen
Perform chemical reactions (for energy)
Eliminate carbon dioxide and waste products 
Synthesise proteins and cell components
control exchange of materials
Adapt, respond to environmental changes

Question 2

What is homeostasis?

Answer 2

Homeo-similar Stasus-condition

refers to the existence or maintenance of a stable internal environment

Question 3

At what level is homeostasis maintained?

Answer 3

The Cellular level

Question 4

What does it mean if homeostasis is maintained at a higher level?

Answer 4

It reflects combined,coordinated actions of many cells

Question 5

What components are in the cell interior?

Answer 5

The nucleus
Cytoplasm
- cytosol (gel-like fluid)
-cell organelles (membranous/non-membranous)

Question 6

What components are in the cell exterior?

Answer 6

Extracellular fluid (interstitial fluid)

Question 7

What else is the cell membrane know as?

Answer 7

Plasma membrane

Plasmalemma

Question 8

What is the Cell Membrane?

Answer 8

Its is a phospholipid bilayer made up of proteins, lipids and carbohydrates

Question 9

What are the 4 functions of the cell membrane?

Answer 9

1. Physical Isolation
2. regulation of exchange with the environment
3. communication between the cell and its environment
4. structural support

Question 10

What is the structure of the nucleus?

Answer 10

• nuclear envelope
• chromatin
• Nucleolus

Question 11

What is the nuclear envelope?

Answer 11

A barrier that surrounds the nucleus, interrupted by nucleus pores.

Question 12

What is chromatin?

Answer 12

A network of fibres made of protein and dna. When cells divide, chromatin condenses into chromosomes.

Question 13

What is the nucleolus?

Answer 13

Coiled structure composed of ribonucleic acid (RNA) and proteins associated with DNA/

Question 14

What is the function of the nucleus?

Answer 14

Stores and transmits genetic information in the form of DNA to synthesise proteins.

Question 15

What are Membranous organelles surrounded by?

Answer 15

Lipid membranes.

Question 16

What are membranous organelles?

Answer 16

endoplasmicreticulum(ER),Golgiapparatus,lysosomes, peroxisomes, mitochondria

Question 17

What are non-membranous organelles always in contact with?

Answer 17

The cytosol

Question 18

What are non-membranous organelles?

Answer 18

cytoskeleton,microvilli,centrioles,cilia,ribosomes,proteosomes.

Question 19

What is the structure of the endoplasmic reticulum (ER)?

Answer 19

network of membranous channels extending throughout the
cytoplasm
– two forms:
•Granular(Rough),withribosomesattached
• Agranular(Smooth)

Question 20

What are the functions of the ER?

Answer 20

• Rough ER:
– Packaging and transport of proteins secreted by cell or distributed to other cell organelles
• SmoothER:
– Lipid synthesis
– Storage and release of calcium for muscle contraction & other cell activities

Question 21

What is the structure of Golgi apparatus?

Answer 21

-Stacks of flattened membranes (cisternae) containing chambers
– Found near the nucleus

Question 22

What is the function of the golgi apparatus?

Answer 22

-Storage, alteration and packaging of secretory products &
lysosomal enzymes
– for transport to plasma membrane

Question 23

What are the types of Vesicles in the Golgi Apparatus?

Answer 23

– Secretory vesicles–exocytosis

– Membrane renewal vesicles
– Lysosomes

Question 24

What are the structures of Lysosomes?

Answer 24

Vesicles containing digestive enzymes

Question 25

What is the function of lysosomes?

Answer 25

Interacellular removal of damaged organelles or pathogens.

Question 26

What is the structure of Peroxisome?

Answer 26

Vesicles containing degradative enzymes

Question 27

What is the function of peroxisome?

Answer 27

Catabolism of fats and other organic compounds; neutralisation of toxic compounds generated in the process

Question 28

What is the mitochondrion otherwise known as?

Answer 28

The powerhouse of the cell.

Question 29

Describe 6 points about the mitochondrion

Answer 29

• It has a double membrane • Outer membrane surrounds the organelle • Inner membrane contains numerous folds (cristae) • Cristae increase the surface area exposed to the fluid content of matrix • Metabolic enzymes in the matrix catalyse the reactions that provide energy for cellular functions • Adenosine Triphosphate (ATP) is produced, which provides energy to the cell (~95%)

Question 30

What is the structure of ribosomes?

Answer 30

– fixed to the rough ER, or – as free ribosomes scattered in the cytoplasm

Question 31

What does each ribosome consist of?

Answer 31

Protein and RNA

Question 32

What is the function of Ribosomes?

Answer 32

Synthesis of proteins from amino acids using information carried by RNA molecules, from DNA in the nucleus

Question 33

Where do proteins synthesised on free ribosomes go?

Answer 33

They pass into the cytosol

Question 34

Where do proteins synthesised by the Er go?

Answer 34

They go to the Golgi Apparatus

Question 35

What are three points about Centrioles?

Answer 35

• Direct movement of chromosomes in cell division • Organise the cytoskeleton • Cytoplasm surrounding them is the centrosom

Question 36

What are two points about the cilia?

Answer 36

- anchored by a basal body | - movement of materials (fluids) across cell surface

Question 37

What is a key point about proteosomes?

Answer 37

Breakdown and recycling of damaged or abnormal proteins (contain protein-digesting enzymes called proteases)

Question 38

What are two points about the Cytoskeleton?

Answer 38

-Proteins organised in fine filaments or slender tubes -Provides skeletal strength & flexibilit

Question 39

What is a key point about the microvilli?

Answer 39

Increase surface area to facilitate absorption of extracellular materials

Question 40

Why is plasmalemma said to be selectively permeable?

Answer 40

It allows for free passage of some molecules and restricts the passage of other

Question 41

What type of ribosome can be found attached to the rough ER?

Answer 41

Fixed ribosomes