Chap 1: Cells Flashcards
What is the difference between animal and plant cells?
Plant has a cell wall, chloroplasts and a large central vacuole
Animal cell: no cell wall & chloroplast with small vacuoles
Which parts of the cell can only be seen with an electron microscope?
Endoplasmic reticulum, golgi body, mitochondria and ribosomes
What is cell membrane and what does it do?
- A partially permeable membrane that only allow some substances to pass
- Controls the movement of substances in & out of the cell
What is cell wall and what does it do?
- A fully permeable membrane that does not control substances that enter/leave the cell
= Protects cell from injury and gives it a fixed shape
What is cytoplasm and what does it do?
- A jelly like substance that contains organelles
- A place where most cell activities occur
What is the nucleus and what does it do?
= Surrounds the nuclear membrane and contains genetic information from chromosomes
- Controls all cell activities and is essential for cell division
Which organelles are a part of the nucleus?
Chromosomes & nuclear membrane
What are chromosomes?
Contains proteins and DNA which carries instructions for cell activities - human has 46 chromosomes
What is the nuclear membrane?
It separates the nucleus content from the rest of the cytoplasm
What is the rough endoplasmic reticulum?
- An organelle lined with the membrane containing ribosomes that synthesises proteins
- Transports ribosome-made proteins to Golgi body for secretion out of cell
What are ribosomes and what do they do?
- Small round structures that is used to synthesise proteins in the cell
- Found attached to RER - make proteins that are transported out of cell
- Also found lying freely in cytoplasm which makes proteins used within the cytoplasm
What is the smooth endoplasmic reticulum?
- An organelle attached to the RER with no ribosomes
- It synthesises fats & steroids and detoxifies harmful substances
What is the Golgi body (Golgi apparatus)?
- Surrounds membrane which contains vesicles
- Chemically modifies substances made by ER and stores & packages these substances in vesicles for secretion
What is the mitochondria? (singular: mitochondrion)
- An organelle used for aerobic respiration when food substances are broken down to release energy for growth & reproduction
What are chloroplasts?
- An organelle containing chlorophyll which is essential for photosynthesis
What are vacuoles?
- An organelle enclosed by partially permeable membrane that store substances within the cell
What are vacuoles in plant cells used for?
Contains dissolved substances like sugar, mineral salts, amino acids etc
What are vacuoles in animal cells used for?
Contains food and water substances temporarily
What are the special features of a red blood cell? (hint: 4)
- Cytoplasm containing haemoglobin
- Circular, biconcave shape
- Lacks nucleus
- Flexible
How does cytoplasm containing haemoglobin help the red blood cells?
haemoglobin - red pigment
It binds to oxygen and transports it to the body
How does a circular, biconcave shape help the red blood cells?
It increases surface area to volume ratio which helps oxygen diffuse in & out at a higher rate
How does no nucleus help the red blood cell?
It helps contains more haemoglobin for transport of oxygen
How does being flexible help the red blood cells?
It can squeeze through the capillaries easily, hence faster transportation
What are the special features of a muscle cell? (hint: 2)
- Elongated with cylindrical shape
- Has mitochondria
How does an elongated, cylindrical shape help the muscle cell?
It helps to contain many nuclei and mitochondria
How does mitochondria help the muscle cell?
It provides energy for the contraction of muscle cells
What is the special feature of a root hair cell?
- Long, narrow root hair
How does a long narrow root hair benefit the root hair cell?
It increases the surface area to volume ratio which helps to absorb water and mineral salts at a faster rate
