Grade 10 Biology Flashcards
1
Q
Cell Membrane (3)
A
- Semi-permeable phospholipid bilayer
- forms a protective barrier around the cell that is composed of a double layer of lipids (fat-like molecules)
- Semi-permeable because it regulates the passage of substances into and out of the cell.
2
Q
Cytoplasm
A
jelly-like liquid in which the cell organelles are suspended
3
Q
Cytoskeleton (3)
A
- basic structural framework of the cell
- necessary for cell shape, mechanical support, cell division, movement of the cell as a whole, and movement of organelles within the cell
- composed of a network of fibers made of protein filaments
4
Q
Nucleus (5)
A
- control centre
- directs all cellular activities
- contains genetic material (DNA) of the cell
- DNA is organized into discrete units called
- chromosomes: structures that carry coded instructions for all cell activity
5
Q
Nuclear Membrane (2)
A
- surrounds the nucleus
2. composed of two porous layers allowing for certain substances to pass through
6
Q
Nucleolus (3)
A
- a densely packed ball of DNA, RNA and protein
- used to make ribosomes
- only visible when the cell isn’t dividing
7
Q
Chromosomes (5)
A
- found in the nucleus
- composed of DNA and protein and contain all genetic information passed on from parent to offspring
- there are a set number of chromosomes per species, ex: human cell has 46 chromosomes but human sex cell (egg or sperm) has only 23
- the portion of a chromosome that “codes” for a particular trait is called a gene
- When the cell isn’t dividing, chromosomes are present as chromatin, long uncoiled thread-like strands of DNA.
8
Q
Centrosome/Centrioles (4)
A
- found near nucleus, only in animal cells
- organizes microtubules in the cell
- made up of a pair of centrioles: paired cylindrical organelles near the nucleus composed of microtubules, lie at right angles to each other
- involved in cell division (needed to make spindle fibers)
9
Q
Mitochondrion (4)
A
- a double-layered, sausage-shaped structure that encloses inner folds called cristae
- known as the “powerhouse” of the cell because it produces the chemical energy (ATP) that fuels cellular activities by a process called cellular respiration:
- Glucose + oxygen → carbon dioxide + water
+ energy - C6H12O6 (s) + 6O2 (g) → 6CO2 (g) + 6H2O (g)
+ energy
10
Q
Endoplasmic Reticulum (4)
A
- a network of interconnected small tubes extending from nuclear membrane to cell membrane
- manufactures and transports materials such as proteins and fats throughout the cell
- rough ER: contains ribosomes
- the smooth ER does not have ribosomes on it
11
Q
Smooth ER (2)
A
- contains many enzymes and is involved in several metabolic processes such as the synthesis of lipids, phospholipids and steroids
- also stores calcium ions
12
Q
Rough ER
A
Responsible for synthesizing and transporting proteins
13
Q
Ribosomes (3)
A
- manufacture proteins
- can be found embedded in the rough endoplasmic reticulum or dispersed throughout the cytoplasm
- make up 25 % of the total mass of the cell
14
Q
Golgi Bodies/ Golgi Apparatus (3)
A
- membrane structures found near the nucleus
- composed of numerous layers
- they receive proteins (via transport vesicles) from the endoplasmic reticulum and modify, sort and package these proteins for delivery throughout and out of the cell
15
Q
Lysosome (4)
A
- small membrane bags containing enzymes
- aid in digestion of proteins, fats and carbohydrates
- involved in the recycling of organelles, the destruction of cells, and also help fight infection by breaking down invading bacteria
- often called the “suicide sacs”