(Physiology)- The Cell (Lec. 1)

Question 1

What is homeostasis

WHERE IS HOMEOSTASIS REGULATED

Answer 1

• the ability to maintain a stable internal environment in an ever-changing outside world
• in the hypothalamus, it receives input and controls hormones

Question 2

What must homeostasis keep constant in the body?

Answer 2

Nutrients / wastes
O 2 / CO2 levels
pH
Water/electrolytes
Temperature
Blood volume
Blood pressure

Question 3

What is circadian rhythm

Answer 3

Circadian rhythm is the 24-hour internal clock in our brain that regulates cycles of alertness and sleepiness by responding to light changes in our environment. Our physiology and behavior are shaped by the Earth’s rotation around its axis.

Question 4

positive and negative feedback loops

examples

Answer 4

Positive feedback moves more into the stimulus and move farther from the balance maintained by homeostasis.

Negative Feedback moves less into the stimulus like when you get to hot, you sweat to cool down.

Positive: In human biology, a positive feedback loop can be seen during childbirth. The release of oxytocin causes uterine contractions, which push the baby toward the cervix. This pressure triggers the release of more oxytocin, increasing the strength and frequency of contractions until delivery.

Negative: A negative feedback loop in human biology helps maintain homeostasis. For example, when body temperature rises, sweat glands are activated to cool the body down. As the temperature returns to normal, the sweating decreases, preventing further cooling and keeping the system in balance.

Question 5

Levels of organization of life

Answer 5

CCTOOO
Chemical, cell, tissue, organ, organ system, organism,

Question 6

3 parts of a cell

Answer 6

Cell membrane

Cytoplasm(organelles)

Nucleus(chromosomes/genes)

Question 7

Describe how the function of the

endoplasmic reticulum,

transport vesicles,

Golgi apparatus,

secretory vesicles

plasma membrane is related.

Answer 7

ER: Synthesizes proteins which are then packaged into transport vesicles and are transported to golgi apparatus
Transport Vesicles: Transport vesicles help move materials, such as proteins and other molecules, from one part of a cell to another.
Golgi apparatus: When a cell makes proteins, transporter vesicles help move proteins to the Golgi apparatus for further sorting and refining.
Secretory Vesicles: Secretory Vesicles are located at the end of nerve cells. They help transmit signals from one nerve cell to another by releasing or secreting neurotransmitters that activate receptors in the neighbouring cell. The secretory vesicles send the modified proteins to the plasma membrane.
Plasma Membrane:
The plasma membrane separates the interior of the cell from the outside environment. Provides protection to the cell. Transports nutrients into the cell and toxic substances out of the cell. It regulates the transport of materials that enter and exit the cell. The plasma membrane fuses with the proteins and send the proteins outside of the cell.

Question 8

ribosomes

WHERE:

Answer 8

either free of attached and make protein for the cell

WHERE: muscles

Question 9

Distinguish between the SER and RER.

what cells are these found in?

Answer 9

SER: The SER synthesizes lipids, steroids, and carbohydrates. Metabolizes waste and toxins
and is responsible for the production and secretion of steroid hormones

RER: The RER produces proteins. Said proteins are then folded, sorted, packaged into vesicles, and transported to the golgi apparatus. It is rough do to proteins.

WHERE:
found in liver and pancreas

Question 10

Golgi apparatus

WHERE:

Answer 10

Re packages proteins from RER into a vesicle that can leave the cell

WHERE: pancreas

Question 11

lysosomes

WHERE:

Answer 11

sac of digestive enzymes

used for repair and removal or foreign matter

like a WBC

WHERE: WBC and liver

Question 12

Centrosome/ centrioles

Answer 12

Centrioles play a role in organizing microtubules that serve as the cell’s skeletal system. Centrioles determine the locations of the nucleus and other organelles within the cell.

Question 13

cytoskeleton

functions of makeup

can it be outside the cell?

WHERE ARE THEY FOUND

Answer 13

Acts as bones and muscle of cell

M.I.M

• Microtubules - transport secretory vesicles, assist in mitosis and form mitotic spindle during cell division
• Microfilaments - contractile systems, muscle, mechanical stiffeners
• Intermediate - resist mechanical stress, hair skin, keratin

MUSCLE CELLS
TRACHEA

Question 14

mitochondria

WHERE:

Answer 14

energy organelle

site of ATP production and enzymes fot TCA and ETC

WHERE: neurons and liver cells

Question 15

cilia and flagella

WHERE:

Answer 15

Cilia
- functions involve locomotion and sensory functions.
- directional movement of particles
- line trachea, move outside particles

Flagella is the organelle for cell movement.

FLAGELLA FOR SPERM

CILIA IN TRACHEA

Question 16

cellular functions and diversity

Answer 16

adult has 100 trillion cells

200 different types
dif shapes and sizes
dif lifespans
Complex tissue or organs

Specialized function of a cell relates to its
- Size
- arrangement of organelles
- bone is dif than catilage which is dif than blood which is dif than muscle

Question 17

aging of cell

Answer 17

cells deteriorate
lose function and can’t respond to stress
losing body cells
worse integrity of extra cellular components

peroxisomes dont detoxify as well so buildup of free radicals as we produce more and take in more

Question 18

Developmental aspects of cells

Answer 18

they are all connected

AGING EFFECTS
- Free radical buildup and damage from byproducts of cellular metabolism
- Radicals buildup and damage cell

MITOCHONDRIAL THEORY
- A decrease in energy production weakens cells

AGING
- genetic theory proposes that aging is programmed by genes and with each replication of DNA, nucleotides are lost
- loss of telomeres which are end caps of chromosomes get removed with time

Question 19

Proteosomes

WHERE:

Answer 19

Large protein complexes
protein-digesting organelles
digest tagged, damaged, or incorrectly folded proteins

get words at job older you are

WHERE: eukaryotic cells

Question 20

The function of the nucleus- one nucleus exception

Golgi apparatus,

cell membrane and lysosome.

Answer 20

Nucleus: The nucleus stores the cell’s DNA, maintains its integrity,and regulates transport of molecules between the cytoplasm and nucleus.
- red blood cells(none) and muscles(multi)

Golgi Apparatus: Proteins and lipids are moved from the RER and SER to the Golgi apparatus inside vesicles. The vesicles fuse with the Golgi membrane and move towards the center. of the cell. They are modified and stored, then transported to other destinations within the cell, or out to the cell membrane as needed.

Cell Membrane: The cell membrane connects and communication to neighbouring cells. And regulates the transport of materials in and out

Lysosome:- Lysosomes aid in the breakdown and digestion of substances through releasing hydrolytic enzymes stored in spherical sac’s composed of a phospholipid membrane. They are only found in animal cells. Breaks down material when it is no longer needed

Question 21

peroxisomes

where

Answer 21

Contains enzymes - involved in various metabolic reactions. Metabolism signalling

lipid synthesis and makes hydrogen peroxide and detoxifies waste products

WHERE: LIVER