(Physiology)- The Cell (Lec. 1) Flashcards
Mastery
What is homeostasis
WHERE IS HOMEOSTASIS REGULATED
- the ability to maintain a stable internal environment in an ever-changing outside world
- in the hypothalamus, it receives input and controls hormones
What must homeostasis keep constant in the body?
Nutrients / wastes
O 2 / CO2 levels
pH
Water/electrolytes
Temperature
Blood volume
Blood pressure
What is circadian rhythm
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.
positive and negative feedback loops
examples
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.
Levels of organization of life
CCTOOO
Chemical, cell, tissue, organ, organ system, organism,
3 parts of a cell
Cell membrane
Cytoplasm(organelles)
Nucleus(chromosomes/genes)
peroxisomes
Contains enzymes - involved in various metabolic reactions. Metabolism signalling
lipid synthesis and makes hydrogen peroxide and detoxifies waste products
Describe how the function of the
endoplasmic reticulum,
transport vesicles,
Golgi apparatus,
secretory vesicles
plasma membrane is related.
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.
The function of the nucleus- one nucleus exception
Golgi apparatus,
cell membrane and lysosome.
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
ribosomes
either free of attached and make protein for the cell
Distinguish between the SER and RER.
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.
Golgi apparatus
Re packages proteins from RER into a vesicle that can leave the cell
lysosomes
sac of digestive enzymes
used for repair and removal or foreign matter
like a WBC
Proteosomes
Large protein complexes
protein-digesting organelles
digest tagged, damaged, or incorrectly folded proteins
get words at job older you are
Centrosome/ centrioles
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.
cytoskeleton
functions of makeup
can it be outside the cell?
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
cellular functions and diversity
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
