Bio: L1-circulatory system Flashcards
Cell theory - three points
- the cell is the basic unit of structure in life
- all living things are made up of one/more cells
- all cells come from pre-existing cells
3 reasons for cell division
Reproduction, growth, repair
Phases of interphase (names and descriptions), talk ab G2 checkpoint
G0 - resting phase: cell is not dividing or preparing to divide (preforms its function)
G1 - Cells grow: get bigger in size, make proteins and organelles, synthesize proteins and RNA (centromere and components of centrosomes are made)
S - synthesis and replication of DNA (DNA is duplicated for there to be enough for both daughter cells)
G2 - cell continues to grow, make proteins and organelles, reorganizes to prep for mitosis.
G2 checkpoint: ensures that DNA is not damaged
4 phases of mitosis
Prophase, metaphase, anaphase, telophase (PMAT)
Duration of interphase on average
24 hours
Duration of mitosis on average
1 hour
What happens during prophase (4)
- Spindle fiber begins to form
- The nucleolus (the organelle that make ribosomes) disappears
- nuclear membrane disintegrates, allowing chromosomes to move freely
- centrosomes move to opposite ends of the cell
What happens during metaphase? (1)
- spindle fibers that came from centrosomes (each containing two centrioles) move chromosomes to the metaphase plate (equator of the cell)
What happens during anaphase? (1)
Each pair of chromosomes is separated into two identical chromosomes by the spindle fiber
What happens during telophase? (3)
- nuclear membrane forms around each set of chromosomes to separate nuclear DNA from the cytoplasm
- chromosomes begin to uncoil
- cell begins to pinch inwards
What happens during cytokinesis? (2)
- This is where the parent cell actually splits into two identical daughter cells.
- When this happens, the cleft formed by the cell membrane pinching in is called the cleavage furrow.
name 12 organelles of a eukaryotic plant cell, + which ones are present in animal cells and which are not
1.Chloroplast (plant only)
2.Endoplasmic reticulum
3.Cell wall (plant only)
4.Nucleus
5.Cell membrane
6.Nuclear membrane
7.Vacuole
8.Mitochondria
9.Cytoplasm
10.Golgi body
11.Ribosomes
12. lysosomes
Functions of each of the following + differences between plant and animal cells:
1.Chloroplast (plant only)
2.Endoplasmic reticulum
3.Cell wall (plant only)
4.Nucleus
5.Cell membrane
6.Nuclear membrane
7.Vacuole
8.Mitochondria
9.Cytoplasm
10.Golgi body
11.Ribosomes
12. lysosomes
Cytoplasm
All organelles are suspended inside of it
Mostly made up of water, also contains salts and organic molecules
Allows organelles to move around
Is the site of many chemical reactions
Cell membrane
Supports the cell, allows substances such as oxygen and water molecules to enter while keeping others such as proteins out
Also surrounds most organelles in a eukaryotic cell
Nucleus
Contains chromosomes, which contain DNA (genetic information)
When a cell divides, DNA is duplicated
Mitochondria
Powerhouse of the cell
Stores energy in the form of glucose
Contains enzymes that convert energy into an easier to use form (cellular respiration)
Cellular Respiration:
Glucose+oxygen → water+CO2+usable energy
In cells where more cellular respiration occurs (ex. Muscle cells), more mitochondria are necessary
Endoplasmic reticulum
3D network of branching tubes and pockets
Extends throughout the cytoplasm
Transport materials throughout the cell
Golgi bodies
Collect and process materials to be removed from the cell
Make and secrete mucus
Vacuole
Single layer of membrane enclosing fluid in a sac
In animal cells, function varies depending on the type of cell (could store waste or regulate cell pressure)
In plant cells, vacuoles keep leaves firm and strong when they are full of water
Cell wall
Outside of cell membrane
Rigid, made out of cellulose
Provides support for cells
Fun fact: cellulose lasts after the cell has died. Paper in books is mostly made up of cellulose from dead cells.
Chloroplast
Absorb light energy, site of photosynthesis
Photosynthesis:
Carbon dioxide + water + energy (sun) → glucose + oxygen
Contain chlorophyll, which gives plants their green colour
Ribosomes
Site of protein synthesis (proteins are made)
Lysosome
Digestive system of the cell: break down compounds from outside, get rid of waste from inside
diffusion
- when a substance is present in different concentrations on opposite sides of the cell membrane, the particles will diffuse
- diffusion: movement of particles from an area of high concentration to an area of low concentraion
explain cancer
Some cells divide often and either are in G0 for a short amount of time or skip G0. Other cells do not divide very often and are in the G0 phase for many years.
When the cell receives the signal to divide, it moves into the G1 phase of the cell cycle.
Cancer cells usually can’t enter G0 and therefore begin to divide uncontrollably
contain an error in the DNA that is replicated to the other cancerous cells
do not perform a specialized function like other cells in our body
malignant vs benign tumour
malignant tumours tend to spread throughout the body (causing more harm) while benign tumours stay in one spot and do not spread)