Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Anatomy & Physiology > Cells > Flashcards

Cells Flashcards

1
Q

Describe plasma (cell) membrane

A
  • encloses cell contents
  • participates in cellular activities
  • regulates what enters and leaves cell (semi-permeable or selectively permeable due to phospholipid bilayer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe plasma (cell) membrane structure

A
  • phospholipid bilayer: main structure with phospholipids as most prevalent molecule
  • proteins within it act as specific transporters or channels
  • cholesterol strengthens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name types of protein in plasma membrane

A
  • channels
  • transporters
  • receptors
  • enzymes
  • linkers
  • cell identity markers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of this protein in the plasma membrane - channels?

A

pores in the membrane that allow passage of specific substances such as ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of this protein in the plasma membrane - transporters?

A

change shape as they shuttle substances, such as glucose, across the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of this protein in the plasma membrane - receptors?

A

allow for attachment of substances, such as hormones, to the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the function of this protein in the plasma membrane - enzymes?

A

participate in reactions at the membrane surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of this protein in the plasma membrane - linkers?

A

help stabilize the plasma membrane and attach cells together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of this protein in the plasma membrane - cell identity markers?

A

unique to a persons’ cells; important in the immune system & transplantation of tissue from one person to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the cytoplasm (consists of)?

A
  • activities of the cell mainly occur here
  • consists of fluid (cytosol) or water with suspended or dissolved substances such as enzymes, glucose, electrolytes (sodium ions)
  • consists of organelles (litle organs) of the cell that perform specific functions (eg nucleus and ribosomes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the plasma membrane and its function.

A
  • outer layer of cell, composed mainly of lipids and proteins
  • encloses cell contents; regulates what enters/leaves cell; participates in growth, reproduction, interactions between cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the microvilli and their function.

A
  • short extensions of the plasma membrane

- absorb materials into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the nucleus and its function.

A
  • large, membrane-bound, dark-staining organelle near center of cell; enclose din nuclear membrane; contains nucleolus where ribosomes are made (required for protein synthesis)
  • control center of cell
  • contains chromosomes (hereditary structures that direct all cell activities, composed of DNA)
  • involved in cell reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the nucleolus and its function.

A
  • small body in the nucleus

- makes ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the cytoplasm and its function.

A
  • colloid that fills the cell from the nuclear membrane to the plasma membrane
  • consists of cytosol & organelles
  • site of many cellular activities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe cytosol and its function.

A
  • fluid portion of cytoplasm
  • contains water, enzymes, nutrients, etc
  • surrounds organelles
  • site of many chemical reactions & nutrient storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the endoplasmic reticulum and its function.

A
  • network of membranes w/in cytoplasm
  • rough ER (rER) has ribosomes attached, smooth does not
  • rough ER modifies, folds & sorts proteins (site of protein synthesis)
  • smooth participates in lipid synthesis (important for making more membranes, detoxifying substances, stores calcium ions in muscle and called sarcoplasmic reticulum)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe ribosomes and their function.

A
  • small bodies free in the cytoplasm or attached to the endoplasmic reticulum
  • composed of RNA & protein
  • not membranous
  • produced in nucleolus but leaves nucleus for cytoplasm (free in cytoplasm or bound to rough endoplasmic reticulum)
  • manufactures proteins (involved in protein synthesis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the Gogi apparatus and its function.

A
  • layers of membranous sacs
  • further modifies proteins
  • sorts & prepares proteins made at ribosomes for transport to other parts of cell or out of cell
  • creates final functional protein for use by or release from cell (eg mucous in digestive tract/hemoglobin in RBCs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe mitochondria and its function.

A
  • tiny organelles w/ internal folded membranes that create separate compartments w/ different enzymes & functions
  • convert energy from nutrients into ATP (aerobic cellular respiration - in presence of O2 convert glucose to energy - ATP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe lysosomes and their function.

A
  • small sacs of digestive enzymes
  • digest substances w/in the cell
  • important for recycling worn out organelles, destroying engulfed bacteria or viruses, self-destruction of a cell, detoxification of drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe peroxisomes and their function.

A
  • membrane-enclosed organelles containing digesting enzymes
  • break down harmful substances
  • important for recycling worn out organelles, destroying engulfed bacteria or viruses, self-destruction of a cell, detoxification of drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe proteasomes and their function.

A
  • barrel-shaped organelles

- destroy improperly synthesized proteins

24
Q

Describe vesicles and their function.

A
  • small membrane-bound sacs in the cytoplasm

- store materials & move into or out of cell

25
Q

Describe centrioles and their function.

A
  • rod-shaped bodies (usually two) near nucleus
  • composed of microtubule proteins
  • help separate chromosomes during cell division so each daughter cell gets proper number
26
Q

Describe surface projections and their function.

A
  • structures that extend from the cell

- move the cell or the fluids around the cell

27
Q

Describe cilia and their function.

A
  • many short hairlike projections from the cell
  • composed of microtubules
  • move fluids around the cell
28
Q

Describe flagellum and their function.

A
  • single long whiplike extension from the cell
  • composed of microtubules
  • moves the cell
29
Q

Name and describe the three types of cell transport.

A
  • passive across plasma membrane: substances cross following their concentration gradients (high to low); eg diffusion, facilitated diffusion, osmosis, filtration
  • active across plasma membrane: energy (ATP) required to move substances; against concentration gradient or for movement of large molecules
  • vesicular: paghocytosis, pinocytosis, exocytosis
30
Q

What is diffusion?

A
  • the constant movement of molecules from an area of high concentration to one of low concentration to achieve equilibrium
  • occurs with or without a plasma membrane
31
Q

Do substances move up or down their concentration gradients during passive diffusion across semi-permeable membrane? Is energy required?

A

down; no

32
Q

Which solutes (dissolved substances) are allowed to cross semi-permeable membrane during passive diffusion? Which are not?

A
  • fat-soluble substances (lipids, alcohol) and water, CO2 and O2 can cross
  • water-soluble substances (proteins, glucose) cannot
33
Q

What is facilitated diffusion? Is energy required?

A

Movement of solutes (charged, water-soluble substances - glucose, amino acids, electrolytes) down their concentration gradient w/ help of transporter proteins that act as channels; energy not required

34
Q

What is osmosis? Do water molecules move from solution of low solutes to one of high solutes or from high solutes to low?

A
  • movement of water across a semi-permeable membrane when solutes cannot move
  • from low solutes (high water) to high solutes (low water)
35
Q

What is osmotic pressure?

A

the force needed to stop the flow of water by osmosis

36
Q

Name the types of solutions and their effect on a cell.

A
  • isotonic: same concentration as fluid w/in cell; no change
  • hypotonic: cytosol more concentrated than surrounding solution; water moves into cell causing it to swell and perhaps burst
  • hypertonic: cytosol less concentrated than surrounding solution; water moves out of cell and it shrinks (crenation)
37
Q

Describe filtration

A
  • mechanical force pushes substance through membrane
  • membrane limits which particles can pass through
  • pores in membrane restrict larger molecules from passing
  • small particles go through & appear in filtrate
  • eg movement of substances out of blood capillaries due to high blood pressure; filtration of blood at kidney nephrons - urine formation
38
Q

What is active transport? Does it require energy?

A
  • the movement of small solute particles in or out of the cell against the concentration gradient
  • requires energy (ATP)
  • requires protein pump (active transporter)
  • important for muscle contraction and neuron function - creates resting membrane potential
39
Q

Name and describe types of vesicular transport?

A
  • phagocytosis: plasma membrane engulfs large particles from surroundings and brings them into cell (eg white blood cells phagocytize bacteria)
  • pinocytosis: plasma membrane engulfs small droplets of liquid from its surrounds and brings it into cell
  • exocytosis: materials moved out of the cell through creation of membrane-bound vesicles; often protein-based substances produced by ribosomes & packaged by Golgi complex (eg mucous secretion from cells lining upper airways; release of neurotransmitters at ends of neurons)
40
Q

What are the two steps involved in protein synthesis?

A
  • transcription (DNA to mRNA)

- translation (mRNA to protein)

41
Q

Where is DNA found? What does it make up? What is its structure and composition?

A
  • found in nucleus
  • makes up 23 pairs of chromosomes in humans
  • double helix (twisting ladder)
  • composed of four types of nucleotides/nitrogenous bases
42
Q

Distinct regions of the DNA of a chromosome make up what?

A
  • Genes, or sequence of nucleotides that code for a protein, determining hereditary traits or genetic diseases
43
Q

What is the location, composition, structure and function of RNA?

A
  • almost entirely in cytoplasm
  • nucleotides contain adenine (A), guanine (G), cytosine (C) or uracil (U)
  • sugar: ribose
  • structure: single strand
  • manufacture proteins according to the codes carried in the DNA (mRNA, rRNA, tRNA)
44
Q

What is the location, composition, structure and function of DNA?

A
  • almost entirely in the nucleus
  • nucleotides contain adenine (A), guanine (G), cytosine (C), or thymine (T0
  • sugar: deoxyribose
  • structure: double-stranded helix formed by nucleotide pairing A-T; G-C
  • makes up chromosomes, hereditary units that control all cellular activities; divided into genes that carry the nucleotide codes for the manufacture of proteins
45
Q

What organelles are involved in transcription (protein synthesis)? What happens during this stage?

A
  • ribosomes, rough endoplasmic reticulum, and Gogli apparatus
  • genes, composed of DNA nucleotides coding for a specific protein, are copied in the nucleus
  • DNA used as template to make messenger RNA or mRNA from free nucleotides suspended in nucleus
  • mRNA leaves nucleus
46
Q

What happens in translation stage of protein synthesis?

A
  • after mRNA leaves the nucleus, it binds to ribosomes in cytoplasm or on rough endoplastic reticulum
  • specific transfer RNA or tRNA molecule reads mRNA nucleotide sequence and brings the correct amino acid to the mRNA on the ribosome
  • as sequence read by more tRNAs, amino acids are joined together forming long protein chain
47
Q

What happens before any cell division?

A

DNA in nucleus precisely copied (mutations can occur)

48
Q

What is mitosis and what is it important for?

A
  • when nucleus of cell divides once; produces two cells genetically identical to each other and parent cell
  • important for growth and repair
49
Q

What is meiosis and what is it important for?

A
  • process where single cell divides twice to produce four cells containing half amount of genetic information
  • genetically unique from parent cell and each other
  • sex cells (sperm and eggs)
  • important for formation of gametes w/ half number of chromosomes (full number restored upon fertilization)
50
Q

What are the four stages of mitosis and meiosis?

A
  • prophase
  • metaphase
  • anaphase
  • telophase (cytoplasm divides)
  • cell divides twice in a row for meiosis
51
Q

What happens during prophase (mitosis)?

A
  • DNA strands coil into chromosomes
  • nucleolus and nuclear membrane disappear
  • centrioles move to opposite poles and form spindle
52
Q

What happens during metaphase (mitosis)?

A
  • chromosomes line up across centre of cell

- chromosomes attach to spindle

53
Q

What happens during anaphase (mitosis)?

A
  • centromeres split

- identical chromosomes move toward opposite centrioles

54
Q

What happens during telophase (mitosis)?

A
  • chromosomes continue to move toward centrioles
  • nuclear membrane forms around each group of chromosomes
  • plasma membrane pinches off in middle of cell to form two new identical daughter cells
55
Q

What is cell aging? What are the types?

A
  • as cells multiply, changes occur that may lead to their damage or death
  • free radical injury: free radicals are highly reactive, destructive compounds produced during cellular activities; they can damage lysosomes which then release their destructive enzymes causing further cell injury; can result in gene mutations that could lead to cancer
  • slowing cell activity
  • apoptosis (preprogrammed cell death); also a normal process for replacing some types of cells that experience lots of wear and tear (eg stomach lining cells)
56
Q

What is the link between cells and cancer?

A
  • certain mutations may cause changes in cells leading to uncontrolled reproduction (cancer)
  • cancer cells form tumours, crowding out normal cells and interfering w/ normal organ function
  • can spread to other areas of body
57
Q

What are risk factors for cancer?

A
  • heredity (breast, colon)
  • carcinogens (cigarette smoke)
  • ionizing radiation (x-rays, UV rays)
  • diets high in fat and calories and low in fibre, fruits and veggies
  • viruses (some leukemias, cervical cancer from human papilloma virus)

Human Anatomy & Physiology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions